题解 | #奥运排序问题#

#include "iostream"
#include "vector"
#include "algorithm"

using namespace std;

struct Country{
    int G, M, P;
    float G_P, M_P;
    int r[4];  // 四种排序方式下的排名
    int number;
};

bool compare1(Country a, Country b){
    return a.G > b.G;
}

bool compare2(Country a, Country b){
    return a.M > b.M;
}

bool compare3(Country a, Country b){
    return a.G_P > b.G_P;
}

bool compare4(Country a, Country b){
    return a.M_P > b.M_P;
}

bool compare5(Country a, Country b){  // 用于恢复原序
    return a.number < b.number;
}

int main(){
    int n, m;
    while(scanf("%d%d", &n, &m) != EOF) {
        vector<Country> temp(n);
        for (int i = 0; i < n; i++) {
            cin >> temp[i].G >> temp[i].M >> temp[i].P;
            temp[i].number = i;
            temp[i].G_P = (float) temp[i].G / (float) temp[i].P;
            temp[i].M_P = (float) temp[i].M / (float) temp[i].P;
        }
        vector<Country> c;  // 实际需要排名的国家
        for (int i = 0; i < m; i++) {
            int x;
            cin >> x;
            c.push_back(temp[x]);  // 选出要求排名的国家
        }

        // 按金牌总数排序，计算 r[0]
        sort(c.begin(), c.end(), compare1);
        c[0].r[0] = 1;
        for (int i = 1; i < m; i++) {
            if (c[i].G == c[i - 1].G) c[i].r[0] = c[i - 1].r[0];
            else c[i].r[0] = i + 1;
        }

        // 按奖牌总数排序，计算 r[1]
        sort(c.begin(), c.end(), compare2);
        c[0].r[1] = 1;
        for (int i = 1; i < m; i++) {
            if (c[i].M == c[i - 1].M) c[i].r[1] = c[i - 1].r[1];
            else c[i].r[1] = i + 1;
        }

        // 按金牌人口比例排序，计算 r[2]
        sort(c.begin(), c.end(), compare3);
        c[0].r[2] = 1;
        for (int i = 1; i < m; i++) {
            if (c[i].G_P == c[i - 1].G_P) c[i].r[2] = c[i - 1].r[2];
            else c[i].r[2] = i + 1;
        }

        // 按奖牌人口比例排序，计算 r[3]
        sort(c.begin(), c.end(), compare4);
        c[0].r[3] = 1;
        for (int i = 1; i < m; i++) {
            if (c[i].M_P == c[i - 1].M_P) c[i].r[3] = c[i - 1].r[3];
            else c[i].r[3] = i + 1;
        }

        // 恢复原序
        sort(c.begin(), c.end(), compare5);

        // 输出
        for(int i = 0;i < m; i++){
            int rank = c[i].r[0], way = 1;
            for(int j = 1; j < 4; j++){
                if(c[i].r[j] < rank){
                    rank = c[i].r[j];
                    way = j + 1;
                }
            }
            cout << rank << ':' << way << endl;
        }
        cout << endl;
    }
}