結構體排序 分別重構三種cmp函式就行了

（注：部落格作為交流使用，切勿抄襲應付作業）

#include<cstdio>
#include<cstring>
#include<cmath>
#include<iostream>
#include<algorithm>
#include<queue>

using namespace std;
const int maxn = 100000 + 7;
int n, c;

struct node {
    int id, sc;
    char name[22];
}a[maxn];

bool cmp1(node a, node b) {
    return a.id < b.id;
}
bool cmp2(node a, node b) {
    if(strcmp(a.name, b.name) == 0) return a.id < b.id;
    return strcmp(a.name, b.name) < 0;
}
bool cmp3(node a, node b) {
    if(a.sc == b.sc) return a.id < b.id;
    return a.sc < b.sc;
}

int main() {

    //char s[22], t[22];
    //scanf("%s %s", s, t);
    //printf("%d\n", strcmp(s, t));

    scanf("%d %d", &n, &c);
    for(int i = 0; i < n; ++i) {
        scanf("%d %s %d", &a[i].id, a[i].name, &a[i].sc);
    }
    if(c == 1) sort(a, a+n, cmp1);
    if(c == 2) sort(a, a+n, cmp2);
    if(c == 3) sort(a, a+n, cmp3);

    for(int i = 0; i < n; ++i)
        printf("%.6d %s %d\n", a[i].id, a[i].name, a[i].sc);

    return 0;
}