动态规划--数位DP

https://www.acwing.com/problem/content/340/

 

#include<iostream>
#include<vector>
using namespace std;
int get(vector<int> v,int l,int r){
    int res=0;
    for(int i=l;i>=r;i--){
        res=res*10+v[i];
    }
    return res;
}
int power10(int n){
    int res=1;
    for(int i=0;i<n;i++){
        res*=10;
    }
    return res;
}
int count(int n,int x){
    vector<int> v;
    while(n){
        v.push_back(n%10);
        n/=10;
    }
    n=v.size();
    int res=0;
    for(int i=n-1-!x ;i>=0;i--){
        if(i<n-1){
            res+=get(v,n-1,i+1)*power10(i);
            if(x==0){
                res-=power10(i);
            }
        }
        if(v[i]==x){
            res+=get(v,i-1,0)+1;
        }else if(v[i]>x){
            res+=power10(i);
        }
    }
    return res;
}
int main(void){
    int a,b;
    while(cin>>a>>b,a||b){
        if(a>b) swap(a,b);
        for(int i=0;i<10;i++){
            cout<<count(b,i)-count(a-1,i)<<" ";
        }
        cout<<endl;
    }
    return 0;
}