ural1057 Amount of Degrees

链接

这题有一点小坑点 就是AX^B  A只能为0或者1  ，剩下的就比较好做的了。

#include <iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<stdlib.h>
#include<vector>
#include<cmath>
#include<queue>
#include<set>
using namespace std;
#define N 100000
#define LL long long
#define INF 0xfffffff
const double eps = 1e-8;
const double pi = acos(-1.0);
const double inf = ~0u>>2;
LL dp[35][35][11];
int d[35];
LL dfs(int i,int e,int k,int b)
{
    if(i==-1)
    return k==0;
    if(!e&&dp[i][k][b] != -1) return dp[i][k][b];
    int mk = e?d[i]:1;
    int ans = 0;
    mk = min(1,mk);
    for(int j = 0 ;j <= mk ;j++)
    {
        if(k-j>=0)
        {
            ans+=dfs(i-1,e&&j==d[i],k-j,b);
        }
    }
    return e?ans:dp[i][k][b] = ans;
}
LL cal(int x,int k,int b)
{
    int g = 0;
    while(x)
    {
        d[g++] = x%b;
        x/=b;
    }
    return dfs(g-1,1,k,b);
}
int main()
{
    int x,y,k,b;
    memset(dp,-1,sizeof(dp));
    while(cin>>x>>y)
    {
        cin>>k>>b;
        cout<<cal(y,k,b)-cal(x-1,k,b)<<endl;
    }
    return 0;
}