Hackerrank 3D Surface Area Solution
.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} .MathJax_SVG_LineBox {display: table!important} .MathJax_SVG_LineBox span {display: table-cell!important; width: 10000em!important; min-width: 0; max-width: none; padding: 0; border: 0; margin: 0}
Madison, is a little girl who is fond of toys. Her friend Mason works in a toy manufacturing factory . Mason has a 2D board of size with rows and columns. The board is divided into cells of size with each cell indicated by it's coordinate . The cell has an integer written on it. To create the toy Mason stacks number of cubes of size on the cell .
Given the description of the board showing the values of and that the price of the toy is equal to the 3d surface area find the price of the toy.
Input Format.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} .MathJax_SVG_LineBox {display: table!important} .MathJax_SVG_LineBox span {display: table-cell!important; width: 10000em!important; min-width: 0; max-width: none; padding: 0; border: 0; margin: 0}
The first line contains two space-separated integers and the height and the width of the board respectively.
The next lines contains space separated integers. The integer in line denotes .
Constraints.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} .MathJax_SVG_LineBox {display: table!important} .MathJax_SVG_LineBox span {display: table-cell!important; width: 10000em!important; min-width: 0; max-width: none; padding: 0; border: 0; margin: 0}
Output Format.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} .MathJax_SVG_LineBox {display: table!important} .MathJax_SVG_LineBox span {display: table-cell!important; width: 10000em!important; min-width: 0; max-width: none; padding: 0; border: 0; margin: 0}
Print the required answer, i.e the price of the toy, in one line.
Sample Input 0.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} .MathJax_SVG_LineBox {display: table!important} .MathJax_SVG_LineBox span {display: table-cell!important; width: 10000em!important; min-width: 0; max-width: none; padding: 0; border: 0; margin: 0} 1 11
Sample Output 0.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} 6
Explanation 0.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} .MathJax_SVG_LineBox {display: table!important} .MathJax_SVG_LineBox span {display: table-cell!important; width: 10000em!important; min-width: 0; max-width: none; padding: 0; border: 0; margin: 0}
The surface area of cube is 6.
Sample Input 1.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} .MathJax_SVG_LineBox {display: table!important} .MathJax_SVG_LineBox span {display: table-cell!important; width: 10000em!important; min-width: 0; max-width: none; padding: 0; border: 0; margin: 0} 3 31 3 42 2 31 2 4
Sample Output 1.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} .MathJax_SVG_LineBox {display: table!important} .MathJax_SVG_LineBox span {display: table-cell!important; width: 10000em!important; min-width: 0; max-width: none; padding: 0; border: 0; margin: 0} 60
Explanation 1.MathJax_SVG_Display {text-align: center; margin: 1em 0em; position: relative; display: block!important; text-indent: 0; max-width: none; max-height: none; min-width: 0; min-height: 0; width: 100%} .MathJax_SVG .MJX-monospace {font-family: monospace} .MathJax_SVG .MJX-sans-serif {font-family: sans-serif} .MathJax_SVG {display: inline; font-style: normal; font-weight: normal; line-height: normal; font-size: 100%; font-size-adjust: none; text-indent: 0; text-align: left; text-transform: none; letter-spacing: normal; word-spacing: normal; word-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0; min-height: 0; border: 0; padding: 0; margin: 0} .MathJax_SVG * {transition: none; -webkit-transition: none; -moz-transition: none; -ms-transition: none; -o-transition: none} .mjx-svg-href {fill: blue; stroke: blue} .MathJax_SVG_LineBox {display: table!important} .MathJax_SVG_LineBox span {display: table-cell!important; width: 10000em!important; min-width: 0; max-width: none; padding: 0; border: 0; margin: 0}
The sample input corresponds to the figure described in problem statement.
Solution in java8
Approach 1.
import java.io.*;
import java.util.*;
import java.text.*;
import java.math.*;
import java.util.regex.*;
public class Solution {
static int surfaceArea(int[][] a, int h, int w) {
int s = 2 * h * w;
for (int i = 0; i < h; i++) {
for (int j = 0; j < w; j++) {
s += a[i][j] * 4;
}
}
for (int i = 0; i < h; i++) {
for (int j = 1; j < w; j++) {
s -= Math.min(a[i][j-1], a[i][j]) * 2;
}
}
for (int i = 1; i < h; i++) {
for (int j = 0; j < w; j++) {
s -= Math.min(a[i-1][j], a[i][j]) * 2;
}
}
return s;
}
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int H = sc.nextInt();
int W = sc.nextInt();
int[][] A = new int[H][W];
for(int Ai = 0; Ai < H; Ai++){
for(int Aj = 0; Aj < W; Aj++){
A[Ai][Aj] = sc.nextInt();
}
}
int result = surfaceArea(A, H, W);
System.out.println(result);
sc.close();
}
}
Approach 2.
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;
public class Solution {
// Complete the surfaceArea function below.
static int surfaceArea(int[][] A) {
int area = 2*(A.length -2)*(A[0].length -2) ;
for(int i = 1 ;i <= A.length -2 ; i++){
for(int j = 1; j<= A[i].length -2 ; j++){
area += Math.max(0,A[i][j] - A[i-1][j]);
area += Math.max(0,A[i][j] - A[i][j-1]);
area += Math.max(0,A[i][j] - A[i+1][j]);
area += Math.max(0,A[i][j] - A[i][j+1]);
}
}
return area;
}
private static final Scanner scanner = new Scanner(System.in);
public static void main(String[] args) throws IOException {
BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
String[] HW = scanner.nextLine().split(" ");
int H = Integer.parseInt(HW[0]);
int W = Integer.parseInt(HW[1]);
int[][] A = new int[H+2][W+2];
for (int i = 0; i < H; i++) {
String[] ARowItems = scanner.nextLine().split(" ");
scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
for (int j = 0; j < W; j++) {
int AItem = Integer.parseInt(ARowItems[j]);
A[i+1][j+1] = AItem;
}
}
int result = surfaceArea(A);
bufferedWriter.write(String.valueOf(result));
bufferedWriter.newLine();
bufferedWriter.close();
scanner.close();
}
}
Approach 3.
import java.io.*;
import java.math.*;
import java.security.*;
import java.text.*;
import java.util.*;
import java.util.concurrent.*;
import java.util.regex.*;
public class Solution {
// Complete the surfaceArea function below.
static int surfaceArea(int[][] A) {
int H=A.length;
int W=A[0].length;
int result = 2 * H * W;
for (int i = 0; i < H; i++) {
for (int j = 0; j < W; j++) {
result += (A[i][j]) * 4;
if(i != 0) {
result -= 2 * Math.min(A[i - 1][j], A[i][j]);
}
if(j != 0) {
result -= 2 * Math.min(A[i][j], A[i][j - 1]);
}
}
}
return result;
}
private static final Scanner scanner = new Scanner(System.in);
public static void main(String[] args) throws IOException {
BufferedWriter bufferedWriter = new BufferedWriter(new FileWriter(System.getenv("OUTPUT_PATH")));
String[] HW = scanner.nextLine().split(" ");
int H = Integer.parseInt(HW[0]);
int W = Integer.parseInt(HW[1]);
int[][] A = new int[H][W];
for (int i = 0; i < H; i++) {
String[] ARowItems = scanner.nextLine().split(" ");
scanner.skip("(\r\n|[\n\r\u2028\u2029\u0085])?");
for (int j = 0; j < W; j++) {
int AItem = Integer.parseInt(ARowItems[j]);
A[i][j] = AItem;
}
}
int result = surfaceArea(A);
bufferedWriter.write(String.valueOf(result));
bufferedWriter.newLine();
bufferedWriter.close();
scanner.close();
}
}
Solution in python3
Approach 1.
#!/bin/python3
import math
import os
import random
import re
import sys
# Complete the surfaceArea function below.
def surfaceArea(A):
a = [[0] * (len(A[0]) + 2)]
for row in A:
a.append([0] + row + [0])
a.append([0] * (len(A[0]) + 2))
ans = len(A) * len(A[0]) * 2
for i in range(1, len(a)):
for j in range(1, len(a[i])):
ans += abs(a[i][j] - a[i-1][j])
ans += abs(a[i][j] - a[i][j-1])
return ans
if __name__ == '__main__':
fptr = open(os.environ['OUTPUT_PATH'], 'w')
HW = input().split()
H = int(HW[0])
W = int(HW[1])
A = []
for _ in range(H):
A.append(list(map(int, input().rstrip().split())))
result = surfaceArea(A)
fptr.write(str(result) + '\n')
fptr.close()
Approach 2.
#!/bin/python3
import math
import os
import random
import re
import sys
# Complete the surfaceArea function below.
def surfaceArea(A):
Area = 0
for i in range(len(A)):
for j in range(len(A[i])):
l = min(A[i-1][j], A[i][j]) if i > 0 else 0
u = min(A[i][j-1], A[i][j]) if j > 0 else 0
r = min(A[i][j+1], A[i][j]) if j <len(A[i])-1 else 0
d = min(A[i+1][j], A[i][j]) if i <len(A)-1 else 0
k = A[i][j]*4 +2 -l -u -r -d
Area+= k
return(Area)
if __name__ == '__main__':
fptr = open(os.environ['OUTPUT_PATH'], 'w')
HW = input().split()
H = int(HW[0])
W = int(HW[1])
A = []
for _ in range(H):
A.append(list(map(int, input().rstrip().split())))
result = surfaceArea(A)
fptr.write(str(result) + '\n')
fptr.close()
Approach 3.
#!/bin/python3
import math
import os
import random
import re
import sys
# Complete the surfaceArea function below.
def surfaceArea(A,H,W):
area=0
for i in range(H):
for j in range(W):
sub_area=(4*A[i][j]+2)
if i-1>=0:
sub_area-=min(A[i-1][j],A[i][j])
if j-1>=0:
sub_area-=min(A[i][j-1],A[i][j])
if i+1<=H-1:
sub_area-=min(A[i+1][j],A[i][j])
if j+1<=W-1:
sub_area-=min(A[i][j+1],A[i][j])
print(str(i)+" "+str(j)+" is "+str(sub_area))
area+=sub_area
return area
if __name__ == '__main__':
fptr = open(os.environ['OUTPUT_PATH'], 'w')
HW = input().split()
H = int(HW[0])
W = int(HW[1])
A = []
for _ in range(H):
A.append(list(map(int, input().rstrip().split())))
result = surfaceArea(A,H,W)
fptr.write(str(result) + '\n')
fptr.close()
Solution in cpp
Approach 1.
#include <bits/stdc++.h>
using namespace std;
// Complete the surfaceArea function below.
int surfaceArea(vector<vector<int>> A, int H, int W) {
int s = 2 * H * W;
for (int i = 1; i < H + 1; i++) {
for (int j = 1; j < W + 1; j++) {
if (A[i][j] > A[i][j - 1]) s += A[i][j] - A[i][j - 1];
if (A[i][j] > A[i - 1][j]) s += A[i][j] - A[i - 1][j];
if (A[i][j] > A[i][j + 1]) s += A[i][j] - A[i][j + 1];
if (A[i][j] > A[i + 1][j]) s += A[i][j] - A[i + 1][j];
}
}
return s;
}
int main() {
ofstream fout(getenv("OUTPUT_PATH"));
int H, W;
cin >> H >> W;
vector<vector<int>> A(H + 2, vector<int>(W + 2));
for (int i = 0; i < H + 2; i++) {
for (int j = 0; j < W + 2; j++) {
if (i && j && i < H + 1 && j < W + 1) cin >> A[i][j];
else
A[i][j] = 0;
}
}
int result = surfaceArea(A, H, W);
fout << result << "\n";
fout.close();
return 0;
}
Approach 2.
#include <iostream>
using namespace std;
int mod(int a);
int main()
{
const int MAX_SIZE = 102;
int rows, cols,price,i,j;
int mat[MAX_SIZE][MAX_SIZE];
cin >> rows >> cols;
//we surround the matrix with 0s
for (i = 0; i < rows + 2; i++)
{
mat[i][0] = 0;
mat[i][cols+1] = 0;
}
for (i = 0; i < cols + 2; i++)
{
mat[0][i] = 0;
mat[rows+1][i] = 0;
}
//We read the values
for (i = 1; i <= rows; i++)
for (j = 1; j <= cols; j++)
cin >> mat[i][j];
//We compute up and down views.
price = (rows * cols)* 2;
//We compute from left to right view and from behind to infront view
for (int i = 0; i < rows+1; i++)
{
for (int j = 0; j < cols+1; j++)
{
price += mod(mat[i][j] - mat[i][j+1]);
price += mod(mat[i][j] - mat[i+1][j]);
}
}
cout << price << endl;
return 0;
}
int mod(int a)
{
if (a < 0)
a = -a;
return a;
}Approach 3.
#include <bits/stdc++.h>
using namespace std;
bool isValid(int i, int j, int n, int m){
if(i < 0 || j < 0 || i >= n || j >= m)
return false;
return true;
}
int main() {
int n, m;
cin>>n>>m;
int A[n][m];
for (int i = 0; i < n; ++i){
for(int j = 0; j < m; j++)
cin>>A[i][j];
}
int ans = 0;
for (int i = 0; i < n; ++i){
for(int j = 0; j < m; j++){
if(A[i][j] > 0){
ans += 2;
// -------------
if(isValid(i-1,j, n, m)){
if(A[i][j] > A[i-1][j])
ans += (A[i][j] - A[i-1][j]);
}
else{
ans += A[i][j];
}
// -------------
if(isValid(i+1,j, n, m)){
if(A[i][j] > A[i+1][j])
ans += (A[i][j] - A[i+1][j]);
}
else{
ans += A[i][j];
}
// -------------
if(isValid(i,j-1, n, m)){
if(A[i][j] > A[i][j-1])
ans += (A[i][j] - A[i][j-1]);
}
else{
ans += A[i][j];
}
// -------------
if(isValid(i,j+1, n, m)){
if(A[i][j] > A[i][j+1])
ans += (A[i][j] - A[i][j+1]);
}
else{
ans += A[i][j];
}
}
}
}
cout << ans << endl;
return 0;
}
