P1280 尼克的任务（逆序更新）

 

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 1e4 + 10;
int n,k,b[maxn],dp[maxn];
struct node{
    int p,t;
}a[maxn];
bool cmp(node b,node c){
    if(b.p != c.p)
        return b.p > c.p;
    return b.t > c.t;
}
signed main(){
    //freopen("in","r",stdin);
    ios::sync_with_stdio(0);
    cin >> n >> k;
    for(int i = 1; i <= k; i++)
        cin >> a[i].p >> a[i].t,b[a[i].p]++;
    sort(a + 1, a + 1 + k,cmp);
    int cnt = 1;
    for(int i = n; i >= 1; i--){
        if(!b[i])
            dp[i] = dp[i + 1] + 1;
        else{
            for(int j = 1; j <= b[i]; j++){
                dp[i] = max(dp[i],dp[i + a[cnt++].t]);
            }
        }
    }
    cout << dp[1] << endl;
    return 0;
}