51Nod 1042 数字0-9的数量 数位DP

#include <iostream>
#include <algorithm>
#define ll long long  
using namespace std;

void dfs(ll a, ll b, ll c[])
{
    ll n = a / 10, m = a % 10, t = n;
    for (int i = 0; i <= m; i++)
        c[i] += b;                //当前位对低位的影响  
    for (int i = 0; i < 10; i++)
        c[i] += b*n;            //高位对低位的影响
    c[0] -= b;                    //0特殊处理，将多算的0减去  
    while (t){                    //当前位对高位的影响  
        c[t % 10] += b*(m + 1);    //加上0  
        t /= 10;
    }
    if (n)  
        dfs(n - 1, b * 10, c);    //n已经处理过，所以要处理n-1  
}

ll x[20], y[20];

int main()
{
    std::ios::sync_with_stdio(false);
    ll a, b;
    cin >> a >> b;
    dfs(a - 1, 1, x);
    dfs(b, 1, y);
    for (int i = 0; i<10; i++) 
        cout << y[i] - x[i] << endl;
    return 0;
}