題目大意:給定n個數x,求出1..x含有49的數的個數。
題目大意:數位dp,思路和hdu2089差不多。求出1..x不含49的數的個數,相減即可。
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<functional>
#include<cmath>
#include<cctype>
#include<cassert>
#include<climits>
using namespace std;
#define For(i,n) for(int i=1;i<=n;i++)
#define Rep(i,n) for(int i=0;i<n;i++)
#define Fork(i,k,n) for(int i=k;i<=n;i++)
#define ForD(i,n) for(int i=n;i;i--)
#define Forp(x) for(int p=pre[x];p;p=next[p])
#define RepD(i,n) for(int i=n;i>=0;i--)
#define MEM(a) memset(a,0,sizeof(a))
#define MEMI(a) memset(a,127,sizeof(a))
#define MEMi(a) memset(a,128,sizeof(a))
#define INF (2139062143)
#define phiF (1000000006)
#define MAXN (1000000+10)
typedef long long LL;
LL dp[50][20],digit[100];
void calc(){
dp[0][0]=1;
For (i,28)
Rep (j,10)
Rep (k,10){
if (!(j==4&&k==9))
dp[i][j]+=dp[i-1][k];
}
}
LL work(LL x){
int len=0;
while (x){
digit[++len]=x%10;
x/=10;
}
digit[len+1]=0;
LL ans=0;
ForD(i,len){
Rep(j,digit[i])
if (!(j==9&&digit[i+1]==4))
ans+=dp[i][j];
if (digit[i]==9&&digit[i+1]==4) break;
}
return ans;
}
int main(){
calc();
int n;
scanf("%d",&n);
while (n--){
LL x;
scanf("%lld",&x);
printf("%lld\n",x-work(x+1)+1);
}
return 0;
}