【记忆化搜索】Codeforces Round #295 (Div. 2) B - Two Buttons

题意：给你一个数字n,有两种操作：减1或乘2，问最多经过几次操作能变成m；

随后发篇随笔普及下memset函数的初始化问题。自己也是涨了好多姿势。

代码

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<cstdlib>
 #define INF 0x7fffffff;
 using namespace std;
 int DP[], vis[];
 int dp(int n, int m)
 {
     if(n <= ) return INF;
     if(n >= m) {DP[n] = n-m; return DP[n];}
     if(!vis[n])
     {
         vis[n] = ;
         //cout << n << "+++" << endl;
         DP[n] = min(dp(n-, m),  dp(n*, m))+;
     }
     return DP[n];
 }
 int main()
 {
     int n, m;
     while(~scanf("%d%d", &n, &m)){
         memset(DP, 0x3f3f3f3f, sizeof(DP));
         memset(vis, , sizeof(vis));
         //cout << DP[0] << endl;
         printf("%d\n", dp(n, m));
     }
     return ;
 }