Time Limit: 1000/500 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 5003 Accepted Submission(s): 1864
//初始的是时候sum是f(a),枚举一位就减去这一位在计算f(i)的权值,显然sum=0时就是满足的,后面的位数凑足sum位就可以了 //只有sum==0时,满足条件 #include<cstdio> #include<cstring> using namespace std; const int N=1e4+5; int cas,A,b,a[12],dp[12][N],all; int f(int x){ if(!x) return 0; return (f(x/10)<<1)+(x%10); } int dfs(int pos,int sum,bool limit){ if(!pos) return sum<=all; if(sum>all) return 0; if(!limit && dp[pos][all-sum]!=-1) return dp[pos][all-sum]; int up=limit?a[pos]:9; int ans=0; for(int i=0;i<=up;i++){ ans+=dfs(pos-1,sum+i*(1<<pos-1),limit && i==a[pos]); } if(!limit) dp[pos][all-sum]=ans; return ans; } int solve(int x){ int pos=0; for(;x;x/=10) a[++pos]=x%10; return dfs(pos,0,1); } int main(){ memset(dp,-1,sizeof dp); scanf("%d",&cas); for(int i=1;i<=cas;i++){ scanf("%d%d",&A,&b); all=f(A); printf("Case #%d: %d\n",i,solve(b)); } return 0; }
原文:http://www.cnblogs.com/shenben/p/6411509.html