【POJ 2970】The lazy programmer（优先队列+贪心）

#include<cstdio>
#include<queue>
#include<algorithm>
#include<cstring>
using namespace std;
//typedef long long LL;
const int maxn = 100005;
int n;
struct Node{
    int a,b;
    int d;
    Node(int a = 0,int b = 0,int d = 0):a(a),b(b),d(d){};
    friend bool operator <(Node p,Node q){
        if(p.a != q.a)
            return p.a < q.a;
        else
            return p.d < q.d;
    }
}node[maxn];
bool cmp1(Node p,Node q){
    return p.d < q.d;
}
int main(){
    while(scanf("%d",&n) != EOF){
        for(int i = 0; i < n; i++){
            scanf("%d%d%d",&node[i].a,&node[i].b,&node[i].d);
        }
        sort(node,node + n,cmp1);
        priority_queue<Node>q;
        int sum = 0;
        double ans = 0.0;
        for(int i = 0; i < n; i++){
            q.push(node[i]);
            sum += node[i].b;
            if(sum > node[i].d){
                while(sum != node[i].d){
                    Node now = q.top(); q.pop();
                    int  need = sum - node[i].d;              //需要补偿的时间
                    if(now.b <= need){
                        ans += 1.0 * now.b / now.a;
                        sum -= now.b;
                    }
                    else{
                        now.b -= need;
                        ans += 1.0 * need / now.a;
                        sum -= need;
                        q.push(now);
                    }
                }
            }
        }
        printf("%.2f\n",ans);
    }
    return 0;
}