HDU-4734-F(x)

3
0 100
1 10
5 100

Case #1: 1
Case #2: 2
Case #3: 13

#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#include <string>
#include <algorithm>
#include <queue>
using namespace std;
int dp[12][4600];
int A,B;
int F;
vector <int> digit;
void init(){
    F = 0;
    int t = 0;
    while(A){
        F += (A%10)*(1<<t);
        t++;
        A/=10;
    }
}
int dfs(int pos,int val,int done){
    if(pos==-1) return 1;
    if(!done&& ~dp[pos][val]) return dp[pos][val];
    int res = 0;
    int end = done?digit[pos]:9;
    for(int i = 0; i <= end; i++){
        if(val + i*(1<<pos) > F) break;
        res += dfs(pos-1,val + i*(1<<pos),done&&i==end);
    }
    if(!done) dp[pos][val] = res;
    return res;
}
int solve(int num){
    digit.clear();
    while(num){
        digit.push_back(num%10);
        num /= 10;
    }
    return dfs(digit.size()-1,0,1);
}
int main(){
    int ncase,T = 1;
    cin >> ncase;
    memset(dp,-1,sizeof dp);
    while(ncase--){
        cin >> A >> B;
        init();
        printf("Case #%d: %d\n",T++,solve(B));
    }
    return 0;
}