B - Bomb

The counter-terrorists found a time bomb in the dust. But this time the terrorists improve on the time bomb. The number sequence of the time bomb counts from 1 to N. If the current number sequence includes the sub-sequence “49”, the power of the blast would add one point.
Now the counter-terrorist knows the number N. They want to know the final points of the power. Can you help them?

Input

The first line of input consists of an integer T (1 <= T <= 10000), indicating the number of test cases. For each test case, there will be an integer N (1 <= N <= 2^63-1) as the description.

The input terminates by end of file marker.

Output

For each test case, output an integer indicating the final points of the power.

Sample Input

3
1
50
500

Sample Output

0
1
15

Hint

From 1 to 500, the numbers that include the sub-sequence “49” are “49”,“149”,“249”,“349”,“449”,“490”,“491”,“492”,“493”,“494”,“495”,“496”,“497”,“498”,“499”,
so the answer is 15.

#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <iostream>
#include <cstring>
using namespace std;

typedef long long ll;

ll dp[110][2], x[110];//x保存数的每一位 
ll v[110];
ll n;

ll dfs(int pos, int pre, int state, bool limit)//第pos位，上一位的数字，上一位是否为4，是否到达上限
{
	ll sum = 0;
	if (pos == -1)//这个数枚举完了 
		return 0;  //返回1表示是合法的 
	if (!limit && dp[pos][state] != -1)//记忆化
		return dp[pos][state];  
	int up = (limit ? x[pos] : 9);//根据limit确定上限
	for (int i = 0; i <= up; i++)//枚举，把不同情况的个数加到sum 
	{
		if (pre == 4 && i == 9)	
			sum += limit ? n % v[pos] + 1 : v[pos];
		else
			sum += dfs(pos - 1, i, i == 4, limit && i == x[pos]);//递归
	}
	if(!limit)//记录状态  
		dp[pos][state] = sum;
	return sum;
}

ll f(ll t)
{
	int pos = 0;
	memset(dp, -1, sizeof dp);
	while (t)//提取每一位
	{
		x[pos++] = t % 10;
		t /= 10;
	}
	return dfs(pos - 1, -1, 0, true);//从最高位开始递归
}

int main(void)
{
	v[0] = 1;
	for (int i = 1; i <= 20; i++){
		v[i] = v[i - 1] * 10;
	}
	//memset(dp, -1, sizeof(dp));
	int t;
	scanf("%d", &t);
	while (t--)
	{
		scanf("%lld", &n);
		printf("%lld\n", f(n));
	}
	return 0;
}