P2602 [ZJOI2010] 数字计数

经典计数问题，注意0的判断 所以要引入前导0标记

#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int,int>;
#define int long long
const int N = 1e5+10;
const int inf = 0x3f3f3f3f;
const int mod = 1e9+7;
int gcd(int a,int b){return b?gcd(b,a%b):a;}
int lcm(int a,int b){return a*b/gcd(a,b);}
int qmi(int a,int b,int mod){int res=1;while(b){if(b&1)res=res*a%mod;b>>=1;a=a*a%mod;}return res;}


int n,q,m;


int dp[35][35];
int ans[N];
int digit1,num1;
int a[N];

int dfs(int len,int s,int limit,int lead){
	if(s>num1)return 0;
	if(!len)return s==num1;
	if(!lead&&!limit&&~dp[len][s])return dp[len][s];
	
	int up = limit?a[len]:9;
	
	int res = 0;
	for(int i=0;i<=up;++i){
		if(i==digit1){
			if(!digit1&&lead)res+=dfs(len-1,s,limit&&i==up,lead&&i==0);
			else res+=dfs(len-1,s+1,limit&&i==up,lead&&i==0);
		}
		else res+=dfs(len-1,s,limit&&i==up,lead&&i==0);
	}	
	
	return limit?res:(lead?res:dp[len][s] = res);
}



int cal(int x){

	memset(dp,-1,sizeof dp);
	int len = 0;
	while(x){a[++len] = x%10;x/=10;}
	
	return dfs(len,0,1,1);
	
}

void solve()
{
	
	int l,r;
	cin>>l>>r;
	
	
	for(int digit=0;digit<=9;++digit){
		for(int num=0;num<=12;++num){
			digit1 = digit;
			num1 = num;
			ans[digit]+=(cal(r)-cal(l-1))*num1;
		}
	}
	
	
	
	for(int i=0;i<=9;i++)cout<<ans[i]<<" ";
	
	

}

signed main()
{
	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	int _;
	//cin>>_;
	_ = 1;
	while(_--)solve();
	return 0;
}