成绩排序

 

 这道题加深了对于sort函数的理解，重构排序规则  bool cmp(a,b)有了一定见解

#include<stdio.h>
#include<algorithm>
#include<string.h>
#include<iostream>
using namespace std;
struct E
{
    char name[1001];
    int age;
    int score;
}buf[1000];

bool cmp(E a, E b)
{
    if (a.score != b.score)             //比较两个数   如果a小 则为真 bool为true  排序为从小到大 即a在前b在后
        return a.score < b.score;
    int tmp = strcmp(a.name, b.name);  
    if (tmp != 0)
        return tmp < 0;
    else
        return a.age < b.age;
}
int main()
{
    int n;
    while (cin>>n)
    {
        for (int i = 0; i < n; i++)
        {
            cin >> buf[i].name >> buf[i].age >> buf[i].score;
        }
        sort(buf, buf + n, cmp);
        for (int i = 0; i < n; i++)
            printf("%s %d %d\n", buf[i].name, buf[i].age, buf[i].score);
    }
    return 0;
}

也可以直接利用C++算符重载直接定义小于运算符

#include<stdio.h>
#include<algorithm>
#include<string.h>
#include<iostream>
using namespace std;
struct E
{
    char name[1001];
    int age;
    int score;
    bool operator < (const E &b) const
    {
        if (score != b.score)
            return score < b.score;
        int tmp = strcmp(name, b.name);
        if (tmp != 0) return tmp < 0;
        else
            return age < b.age;
    }
}buf[1000];


int main()
{
    int n;
    while (cin>>n)
    {
        for (int i = 0; i < n; i++)
        {
            cin >> buf[i].name >> buf[i].age >> buf[i].score;
        }
        sort(buf, buf + n);
        for (int i = 0; i < n; i++)
            printf("%s %d %d\n", buf[i].name, buf[i].age, buf[i].score);
    }
    return 0;
}