poj 3134 Power Calculus

#include<iostream>#include<stdio.h>#include<cmath>#include<queue>#include<stack>#include<algorithm>#include<string.h>#define ll long long#define oo 10000007using namespace std;     int way[1005],num; bool DFSID(int x,int step){       int i;      if (num>step) return false;      if (way[num]==x) return true;      if (way[num]<<(step-num)  < x) return false; // 强力剪枝       for (i=0;i<=num;i++)      {  num++;  way[num]=way[num-1]+way[i];  if (way[num]<=10000 && DFSID(x,step)) return true;   way[num]=way[num-1]-way[i];    if (way[num]>0 && DFSID(x,step)) return true;  num--;      }       return false;    }int main(){        int i,x;      while (~scanf("%d",&x) && x)       { for (i=0;;i++) {      way[num=0]=1;      if (DFSID(x,i)) break; } printf("%dn",i);      }      return 0;}