TIOJ 1174 The Shortest Distance

#include <cstdio>
#include <cstdlib>
#include <algorithm>
using namespace std;
int main(){
    int n, m, ans;
    int a[100005], b[100005];
    scanf("%d %d",&n, &m);
    for (int i = 0; i < n; ++i)
        scanf("%d", &a[i]);
    for (int i = 0; i < m; ++i)
        scanf("%d", &b[i]);
    
    sort(a, a+n);
    sort(b, b+m);

    int x = 0, y = 0;
    ans = abs(a[0] - b[0]);
    while(x < n && y < m){
        ans = min(ans ,abs(a[x] - b[y]));
        if(a[x] < b[y])
            x++;
        else
            y++;
    }

    printf("%d\n", ans);
}