hdu_3555_Bomb(数位DP)

题目连接：hdu_3555_Bomb

题意：和2089一样，只是数据大了点，不过道理是一样的

#include<cstdio>
#include<cstring>
#define F(i,a,b) for(__int64 i=a;i<=b;i++)

__int64 t,n,dp[65][10][2],dig[65],len;

__int64 dfs(int pos,int pre,bool have,bool inf){
    if(!pos)return have;
    if(!inf&&dp[pos][pre][have]!=-1)return dp[pos][pre][have];
    long long end=inf?dig[pos]:9,ans=0;
    F(i,0,end)if(pre==4&&i==9)ans+=dfs(pos-1,i,1,inf&&(i==end));
    else ans+=dfs(pos-1,i,have,inf&&(i==end));
    if(!inf)dp[pos][pre][have]=ans;
    return ans;
}

int main(){
    memset(dp,-1,sizeof(dp));
    scanf("%I64d",&t);
    while(t--){
        scanf("%I64d",&n);
        for(len=0;n;n/=10)dig[++len]=n%10;
        printf("%I64d
",dfs((int)len,0,0,1));
    }
    return 0;
}