时间复杂度

不高

C++ 代码

#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;

int months[13] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };

int check(int y) {
    if ((y % 100 != 0 && y % 4 == 0) || y % 400 == 0)return 1;
    else return 0;
}
struct node {
    int a=0;
    int b=0;
    int c=0;
    int k=0;
}day[5];
int cou = 0;

bool cmp(node a, node b) {
    return a.k < b.k;
}
void res(int a, int b, int c) {
    cou++;
    if (a >= 0 && a <= 59) {
        a = 2000 + a;
    }
    else if (a == 60)a = 1960;
    else a = 1900 + a;
    if (b >= 1 && b <= 12);
    else return ;
    if (b != 2) {
        if (c >= 1 && c <= months[b]);
        else return ;
    }
    if (b==2) {
        if(check(a))
        if (c > 29)return;
        if(!check(a))
        if (c > 28)return ;
    }
        day[cou].a = a;
        day[cou].b = b;
        day[cou].c = c;
        day[cou].k = a * 1000 + b * 100 + c;
}

int main()
{
    int a, b, c;
    char z, x;
    cin >> a >> z >> b >> x >> c;
    res(a, b, c);
    res(c, a, b);
    res(c, b, a);
    sort(day + 1, day + 4, cmp);
    for (int i = 1; i <= 3; i++) {
        if (day[i].k != day[i - 1].k) {
            cout << day[i].a << "-";
            if (day[i].b < 10)cout << "0" << day[i].b << "-";
            else cout << day[i].b << "-";
            if (day[i].c < 10)
                cout << "0" << day[i].c << endl;
            else cout << day[i].c<< endl;
        }
    }
    return 0;
}