P2602 [ZJOI2010]数字计数

#include <bits/stdc++.h>
#define ll long long
#define re register
using namespace std;

template <typename T>void in(T &x) {
    x = 0; T f = 1; char ch = getchar();
    while(!isdigit(ch)) {if(ch == '-') f = -1; ch = getchar();}
    while( isdigit(ch)) {x = 10 * x + ch - 48; ch = getchar();}
    x *= f;
}

template <typename T>void out(T x) {
    if(x < 0) x = -x,putchar('-');
    if(x > 9) out(x/10);
    putchar(x%10 + 48);
}
//---------------------------------------------------------
const int N = 20;
ll a,b;
ll f[N][N];
int num[N];

ll dfs(int pos,int lead,int limit,int digit,int sum) {
    if(pos == 0) return sum;//边界 
    if(lead && !limit && f[pos][sum] != -1) return f[pos][sum];
    //先导不为0 未受限 已算过 -> 返回 
    ll res = 0;
    int up = (limit == 1 ? num[pos] : 9);
    //int up = 9; if(limit) up = num[pos];
    for(int i = 0; i <= up; ++i) {
        res += dfs(pos-1,lead|i,(i==up)&&(limit),digit,sum+((lead|i)&&(i==digit)));    
    }
    if(lead && (!limit)) f[pos][sum] = res;
    return res;
}

ll solve(ll x,int digit) {
    int len = 0;
    while(x) num[++len] = x%10,x/=10;//逆序存数; 
    memset(f,-1,sizeof(f));
    dfs(len,0,1,digit,0);
}

int main() {
    in(a); in(b);
    for(int digit = 0; digit <= 9; ++digit) {
        out(solve(b,digit) - solve(a-1,digit)); putchar(' ');
    }
    return 0;
}