# CAVITY-MAP hackerrank Solution - Correct, Optimal and Working

``````/*
*  Author: Arpit Bhayani
*  https://arpitbhayani.me
*/
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <climits>
#include <deque>
#include <iostream>
#include <list>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <vector>

#define ll long long

#define MIN(a, b) a < b ? a : b
#define MAX(a, b) a > b ? a : b

using namespace std;

int i = 0;
char ch;
while((ch = getchar()) != '\n') {
str[i++] = ch;
}
str[i] = '\0';
return i;
}

char arr[110][110];

int main(int argc, char *argv[]) {
int n;
cin >> n;

for(int i = 0 ; i  < n ; i++) {
scanf("%s", arr[i]);
}

for(int i = 1; i < n-1; i++) {
for(int j = 1; j < n -1 ; j++) {
int d = arr[i][j] - '0';
if(arr[i][j] != 'X' && ((arr[i-1][j] - '0') < d &&
(arr[i+1][j] - '0') < d && (arr[i][j - 1] - '0') < d &&
(arr[i][j+1] - '0') < d)) {
arr[i][j] = 'X';
}
}
}

for(int i = 0 ; i < n ; i++) {
printf("%s\n", arr[i]);
}

return 0;
}
``````