HDU 6150 Vertex Cover （思路 构造）

思路：

链接：https://post.icpc-camp.org/u/ftiasch

#include <cstdio>#include <iostream>#include <string.h>#include <ctime>#include <algorithm>using namespace std;const int maxn = 3030;int main(){    /*for(int n = 2;n <= 200;n++){        int ans = 0;        for(int i = 2;i <= n;i++){            ans += n/i;        }        if(n*2 <= ans){            printf("%d\n",n);        }    }    */    int n = 15,m = 0;    for(int i = 2;i <= 15;i++){        m += n/i * i;    }    m += n;    printf("60 %d\n",m);    int jichu = 0;    for(int i = 1;i <= n;i++){        printf("%d %d\n",i,i+n);    }    int cnt = 1;    for(int i = 2;i <= n;i++){        for(int j = 1;j <= n;){            if(n-j+1 < i) break;            for(int k = 0;k < i;k++){                printf("%d %d\n",n+j+k,n+n+cnt);            }            j += i;            cnt++;        }    }    printf("%d\n",n);    for(int i = 1;i <= n;i++){        printf("%d\n",n+i);    }}