AOJ 2.Home Work

贪心算法

如果在类中定义自定义类型对应sort的比较函数，要注意再比较函数前加上static。说明该函数是静态函数，在内存中占用固定的内存。

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

#define REP(n) for(int o=0;o<n;o++)


class LOVE {
private:
    static const int maxn = 25;
    int M, N;
    struct node {
        int T, V;
        double p;
    }paper[maxn];

    static bool compare_node(node a, node b) {
        return a.p > b.p;
    }

public:
    bool Do() {
        scanf("%d%d", &M, &N);
        if (M == 0 && N == 0)return false;
        REP(M) {
            int T, V;
            scanf("%d%d", &T, &V);
            paper[o].T = T;
            paper[o].V = V;
            paper[o].p = (double)V / (double)T;
        }

        sort(paper, paper + M, compare_node);

        //REP(M)
            //printf("T=%d V=%d p=%f
", paper[o].T, paper[o].V, paper[o].p);

        double ans = 0;
        for (int i = 0; i < M; i++) {
            int temp = N - paper[i].T;
            ans += paper[i].V;
            if (temp < 0) {
                ans += temp*paper[i].p;
                break;
            }
            N = temp;
        }

        printf("%.2f
", ans);
        return true;
    }
};

int main() {
    LOVE LIVE;
    while (LIVE.Do());
    return 0;
}