题解 | 小红的优惠券

#include <cstdio>
#include <iostream>
#include <algorithm>
using namespace std;

struct discount {
    int aj;
    int bj;
};


int main() {
    int n,m;
    scanf("%d %d",&n,&m);
    discount* a = new discount[m];
    for(int i = 0; i < m; i++)
    {
        scanf("%d %d",&a[i].aj, &a[i].bj);
    }
    int max = -1;
    for(int i = 0; i < m; i++)
    {
        if(a[i].aj <= n && a[i].bj > max )
            max = a[i].bj;
    }
    if(max == -1)
        printf("%d",n);
    else
        printf("%d",n-max);
    return 0;
}