【HDOJ】【3709】Balanced Bumber

数位DP

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题解：http://www.cnblogs.com/algorithms/archive/2012/09/02/2667637.html

dfs的地方没太看懂……（也就那里是重点吧喂！）挖个坑……回头再看看

 //HDOJ 3709
 #include<cmath>
 #include<vector>
 #include<cstdio>
 #include<cstring>
 #include<cstdlib>
 #include<iostream>
 #include<algorithm>
 #define rep(i,n) for(int i=0;i<n;++i)
 #define F(i,j,n) for(int i=j;i<=n;++i)
 #define D(i,j,n) for(int i=j;i>=n;--i)
 #define pb push_back
 using namespace std;
 int getint(){
     int v=,sign=; char ch=getchar();
     while(ch<''||ch>''){ if (ch=='-') sign=-; ch=getchar();}
     while(ch>=''&&ch<=''){ v=v*+ch-''; ch=getchar();}
     return v*=sign;
 }
 const int N=,M=;
 typedef long long LL;
 /******************tamplate*********************/

 LL dp[N][N][M];
 int bit[N];
 LL dfs(int pos,int o,int sum,int f){
     if (sum<) return ;
     if (pos==) return sum==;
     if (!f && dp[pos][o][sum]!=-) return dp[pos][o][sum];

     LL ret=;
     int max=f ? bit[pos] : ;
     F(i,,max)
         ret+=dfs(pos-,o,sum+(pos-o)*i,f && i==max);
     if (!f) dp[pos][o][sum]=ret;
     return ret;
 }

 LL cal(LL n){
     int len=;
     for(;n;n/=) bit[++len]=n%;
     LL ret=;
     F(o,,len)
         ret+=dfs(len,o,,);
     return ret-len+;
 }
 int main(){
 #ifndef ONLINE_JUDGE
     freopen("3709.in","r",stdin);
     freopen("3709.out","w",stdout);
 #endif
     memset(dp,-,sizeof dp);
     int T=getint();
     while(T--){
         LL x,y;
         cin >> x >> y;
         cout << cal(y)-cal(x-)<<endl;
     }
     return ;
 }