P1280 尼克的任务

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
int n,k;
struct ta{
    int f;int p;
    int st;
} tas[10001];
int x,y;
int dp[10001];
int fl[10001];
bool cmp(ta x,ta y){
    return x.p>y.p;
}
int fla;
int main(){
    scanf("%d%d",&n,&k);
    for(int i=1;i<=k;++i){
        scanf("%d%d",&x,&y);
        tas[i].p=x;
        tas[i].f=y+x-1;
        tas[i].st=y;
        fl[x]++;
    }
    sort(tas+1,tas+1+k,cmp);
    fla=1;
    for(int i=n;i>=1;--i){
        if(!fl[i])
        dp[i]=dp[i+1]+1;
        else{
        //    dp[i]=0x7f7f7f;
            for(int j=1;j<=fl[i];++j){
            dp[i]=max(dp[i],dp[tas[fla].f+1]);
            fla++;
            }
        }
    }

    cout<<dp[1];
    return 0;
}