Jamie and Interesting Graph CodeForces

http://codeforces.com/problemset/problem/916/C

好尬的题啊。。。

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<vector>
using namespace std;
#define fi first
#define se second
#define mp make_pair
#define pb push_back
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pi;
struct E
{
    int u,v,w;
}e[100100];
int ne;
int n,m;
bool nprime[200100];
int prime[100100],len;
int x=1,y=2;
int main()
{
    int i,j,t;
    nprime[1]=1;
    for(i=2;i<=200000;i++)
    {
        if(!nprime[i])    prime[++len]=i;
        for(j=1;j<=len&&i*prime[j]<=200000;j++)
        {
            nprime[i*prime[j]]=1;
            if(i%prime[j]==0)    break;
        }
    }
    scanf("%d%d",&n,&m);m-=(n-1);
    for(i=1;i<n;i++)    e[++ne]=(E){i,i+1,1};
    for(i=1;i<=m;i++)
    {
        if(y==n)    x++,y=x+2;
        else    y++;
        e[++ne]=(E){x,y,1000000000};
    }
    for(t=0;nprime[t+n-1];t++);
    e[1].w+=t;
    printf("%d %d
",t+n-1,t+n-1);
    for(i=1;i<=ne;i++)    printf("%d %d %d
",e[i].u,e[i].v,e[i].w);
    return 0;
}