HDU 3555 Bomb 数位dp

类似这道题目：HDU 2089 不要62

讲解就略过了，和上面那题完全一样。

#include <algorithm>
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <cstdio>

using namespace std;

typedef long long int LL;
LL dp[65][10];

void init()
{
for (int i = 0; i <= 9; i++)
dp[1][i] = 1;
for (int i = 2; i <= 63; i++)
for (int j = 0; j <= 9; j++)
for (int k = 0; k <= 9; k++)
if (j != 4 || k != 9)
dp[i][j] += dp[i - 1][k];
}

LL cal(LL n)
{
int digit[65], len = 0;
memset(digit, 0, sizeof(digit));
while (n)
{
digit[++len] = n % 10;
n /= 10;
}
LL ans = 0;
for (int i = len; i >= 1; i--)
{
for (int j = 0; j < digit[i]; j++)
ans += dp[i][j];
if (digit[i] == 9 && digit[i + 1] == 4)
break;
}
return ans;
}

int main()
{
//freopen("test.txt", "r", stdin);

int T;
scanf("%d", &T);
init();
while (T--)
{
LL N;
scanf("%I64d", &N);
printf("%I64d\n", N - cal(N + 1) + 1);
}
return 0;
}