CODRFORCES 27E 构造

题目链接：http://codeforces.com/problemset/problem/27/E

代码：

#include <cstdio>#include <iostream>#include <cstring>#define sf scanf#define pf printfusing namespace std;int prim[] = {2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59};typedef long long LL;LL INF = 1e18,ans;int n;void DFS(LL v,int cnt,int pos){//    pf("%lld %lld %d %d\n",ans,v,cnt,pos);    if(cnt > n) return;    if(cnt == n && v <= ans){        ans = v;        return;    }    for(int i = 1;i <= 63;++i){        v *= prim[pos];        if(v <= ans) DFS(v,cnt * (i + 1),pos + 1);        else return;    }}int main(){    sf("%d",&n);    ans = INF;    DFS(1,1,0);    pf("%lld\n",ans);}