[CF959C]Mahmoud and Ehab and the wrong algorithm

解法
很简单对于n<=5举不出反例
如果n>5的话2,3,4好点连1，其他点连2
对于正面例子
直接所有点连1号点
其实就是结论题

代码：

#include <cstdio>

int main(){
    int n;
    scanf("%d", &n);
    if (n <= 5)
        printf("-1\n");
    else{
        printf("1 2\n");
        printf("1 3\n");
        printf("1 4\n");
        for (int i = 5; i <= n; ++i)
            printf("2 %d\n", i);
    }
    for (int i = 2; i <= n; ++i)
        printf("1 %d\n", i);
    return 0;
}

[CF959C]Mahmoud and Ehab and the wrong algorithm

原文：https://www.cnblogs.com/linzhengmin/p/10895911.html