#include <iostream>
//#include <vector>
using namespace std;
 
// Function to return the maximum water that can be stored
int maxWater(int arr[]) {
    int res = 0;
  int n=sizeof(arr)/sizeof(arr[0]);
    for (int i = 1; i <n-1; i++) {
 
        // Find the maximum element on its left
        int left = arr[i];
        for (int j = 0; j < i; j++)
            left = max(left, arr[j]);
 
        // Find the maximum element on its right
        int right = arr[i];
        for (int j = i + 1; j <n; j++)
            right = max(right, arr[j]);
 
        // Update the maximum water
        res += (min(left, right) - arr[i]);
    }
 
    return res;
}
 
int main() {
    int arr[] = { 2, 1, 5, 3, 1, 0, 4 };
   int r= maxWater(arr);
   cout<<r;
    return 0;
}

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