# HackerRank Cavity Map problem solution

In this HackerRank Cavity Map problem, You are given a square map as a matrix of integer strings. Each cell of the map has a value denoting its depth. We will call a cell of the map a cavity if and only if this cell is not on the border of the map and each cell adjacent to it has a strictly smaller depth. Two cells are adjacent if they have a common side or edge.

Find all the cavities on the map and replace their depths with the uppercase character X.

## Problem solution in Python programming.

```n = int(input())
a = [list(input()) for _ in range(n)]

def getval(p, off):
px = p[0] + off[0]
py = p[1] + off[1]
pi = a[px][py]
return 10 if pi == 'X' else int(pi)

for i in range(1, n-1):
for j in range(1, n-1):
p = (i, j)
if getval(p, (0, 0)) > max(getval(p, off) for off in (
(0, 1), (0, -1), (-1, 0), (1, 0))):
a[i][j] = 'X'

for row in a:
print(''.join(row))```

## Problem solution in Java Programming.

```import java.io.*;
import java.util.*;

public class Solution {

public static void main(String[] args) {
/* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution. */
Scanner in = new Scanner(System.in);
int n = Integer.parseInt(in.nextLine());
int[][] array = new int[n][n];
int[][] target = new int[n][n];
for(int i=0; i<n; i++){
String line = in.nextLine();
char[] data = line.toCharArray();
for(int j=0; j<n; j++){
array[i][j] = Character.getNumericValue(data[j]);
//System.out.println(array[i][j]);
}
}
cavityMap(array, target);
for(int i=0; i<n; i++){
for(int j=0; j<n; j++){
if(target[i][j] == -1)
System.out.print("X");
else
System.out.print(array[i][j]);
}
System.out.println("");
}
}

public static void cavityMap(int[][] array, int[][] target) {
int row = array.length;
int col = array[0].length;
for(int i=1; i<row-1; i++){
for(int j=1; j<col-1; j++){
if(isMaximum(array, i, j)){
target[i][j] = -1; // will be translate to X later
}
}
}
}

public static boolean isMaximum(int[][] array, int i, int j) {
int max = Math.max(Math.max(array[i-1][j], array[i+1][j]), Math.max(array[i][j-1], array[i][j+1]));
if(max >= array[i][j])
return false;
else
return true;
}
}```

### Problem solution in C++ programming.

```#include <iostream>
#include <ctime>
#include <fstream>
#include <cmath>
#include <cstring>
#include <cassert>
#include <cstdio>
#include <algorithm>
#include <iomanip>
#include <vector>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <complex>
#include <utility>
#include <cctype>
#include <list>
#include <deque>

using namespace std;

#define FORALL(i,a,b) for(int i=(a);i<=(b);++i)
#define FOR(i,n) for(int i=0;i<(n);++i)
#define FORB(i,a,b) for(int i=(a);i>=(b);--i)

typedef long long ll;
typedef long double ld;
typedef complex<ld> vec;

typedef pair<int,int> pii;
typedef map<int,int> mii;

#define pb push_back
#define mp make_pair

#define MV 4
#define MAXN 102
char A[MAXN][MAXN];
char B[MAXN][MAXN];
int dr[] = {-1,0,1,0};
int dc[] = {0,-1,0,1};
int N;
bool is_cavity(int i, int j)  {
if (i==0 || i==N-1) return false;
if (j==0 || j==N-1) return false;
FOR(mv,MV) {
int i2 = i + dr[mv];
int j2 = j + dc[mv];
if (A[i2][j2] >= A[i][j]) return false;
}
return true;
}

int main() {
cin >> N;
FOR(i,N) scanf("%s",&A[i][0]);
FOR(i,N) FOR(j,N)
if (is_cavity(i,j)) B[i][j] = 'X';
else B[i][j] = A[i][j];
FOR(i,N) cout << B[i] << endl;
}
```

### Problem solution in C programming.

```#include<stdio.h>

int main()
{
int t;
int i,j,n;
scanf("%d",&n);
char a[n+2][n+2];
char b[n+2][n+2];
for(i=0; i<n; i++)
{
scanf("%s",a[i]);
}

for(i=0; i<n ;i++)
{
for(j=0; j<n; j++)
{
if( i > 0 && i < n-1 && j > 0 && j < n-1)
{
char ch = a[i][j];
if(ch > a[i+1][j] && ch > a[i][j+1] && ch > a[i-1][j] && ch > a[i][j-1])
b[i][j] = 'X';
else
b[i][j] = a[i][j];
}
else
b[i][j] = a[i][j];
}
b[i][j] = 0;
}
for(i=0;i<n;i++)
{
printf("%s\n",b[i]);
}

return 0;
}```

### Problem solution in JavaScript programming.

```function processData(input) {
input = input.split('\n')
input.shift()
for (var i = 0; i < input.length ; i++ ){
input[i] = input[i].split("");
}

var output = cavityMap(input);

output.forEach(function(line){
console.log( line.join("") );
})
}

function cavityMap (map) {

var size = map.length-1;
var cavs = [];

for (var i = 1; i < size; i++) {
for (var j = 1; j < size; j++) {
var curr = map[i][j];
if ( curr > map[i-1][j] && curr > map[i+1][j] ){
if (curr > map[i][j-1] && curr > map[i][j+1]) {
cavs.push([i,j]);
}
}

};
};

cavs.forEach(function (cavity){
map[cavity[0]][cavity[1]] = 'X';
})

return map;
}

process.stdin.resume();
process.stdin.setEncoding("ascii");
_input = "";
process.stdin.on("data", function (input) {
_input += input;
});

process.stdin.on("end", function () {
processData(_input);
});```