HDU5802-windows 10-dfs+贪心

音量减的时候，分两种，一种是减到大于目标Ｍ，另一种是减到小于Ｍ，停顿的时候可以减少最后往上加的次数，小于０的时候变成０

然后比一下这两种的最小值。

 /*--------------------------------------------------------------------------------------*/
 #include <algorithm>
 #include <iostream>
 #include <cstring>
 #include <ctype.h>
 #include <cstdlib>
 #include <cstdio>
 #include <vector>
 #include <string>
 #include <queue>
 #include <stack>
 #include <cmath>
 #include <set>
 #include <map>

 //debug function for a N*M array
 #define debug_map(N,M,G) printf("\n");for(int i=0;i<(N);i++)\
 {for(int j=;j<(M);j++){\
 printf("%d",G[i][j]);}printf("\n");}
 //debug function for int,float,double,etc.
 #define debug_var(X) cout<<#X"="<<X<<endl;
 #define LL long long
 const int INF = 0x3f3f3f3f;
 const int LLINF = 0x3f3f3f3f3f3f3f3f;
 /*--------------------------------------------------------------------------------------*/
 using namespace std;

 LL N,M,ans;
 int T;

 LL sum(int x) {return (1LL<<x) - 1LL;}

 LL dfs(LL cur,LL cnt,int stop)
 {
     //printf("cur:%d cnt:%d\n",cur,cnt);
     if(cur == M) return cnt;
     int i = ;
     while(cur-sum(i) > M) i++;

     if(cur -sum(i) == M ) return cnt + i;
     LL up =  M - max(0LL,cur-sum(i) );
     LL res = i + max(0LL,up-stop);
     return min(cnt+res , dfs(cur-sum(i-) , cnt + i,stop+));
 }

 int main()
 {
     scanf("%d",&T);
     while(T--)
     {
         ans = LLINF;
         scanf("%I64d%I64d",&N,&M);
         if(N <= M)
         {
             printf("%I64d\n",M-N);
             continue;
         }

         printf("%I64d\n",dfs(N,,));
     }
 }