50055. Waiting Time at Supermarket

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <ctype.h>
#include <limits.h>

int n, m;
int t, s;

int counter[1024] = {0};

int main(){
    scanf("%d %d", &n, &m);

    long long ans = 0;
    for(int i = 0; i < m; i++){
        scanf("%d %d", &t, &s);

        int min_time = INT_MAX, min_idx;
        for(int j = 0; j < n; j++){
            if(counter[j] < min_time){
                min_time = counter[j];
                min_idx = j;
            }
        }
        if(min_time <= t){
            counter[min_idx] = s + t;
        }
        else{
            ans += (min_time  - t);
            counter[min_idx] += s;
        }
    }
    printf("%lld\n", ans);
}