Search in a matrix

#include <bits/stdc++.h>

#define inp(x) scanf("%d",&x)
#define loop(i,n) for(ll i=0;i<n;++i)
#define pb push_back
#define mp make_pair
#define ll long long

using namespace std;

int main(){
    int t,m,n;
    cin >> t;

    while(t--){
        cin >> m >> n;
        int a[m][n];
        loop(i,m)
            loop(j,n)
                cin >> a[i][j];
        //Start at bottom left
        int key,x=m-1,y=0;
        cin >> key;
        
        while(x>=0 && y<n){
            if(a[x][y] == key){
                cout << 1 << endl;
                goto end;
            }
            (a[x][y] < key) ? (y++): (x--);
        }
        cout << 0 << endl;        
    end:;
    }
    return 0;
}