hdu 3652 B-number(数位DP,4级)
B-number
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)Total Submission(s): 1497 Accepted Submission(s): 820
Problem Description
A wqb-number, or B-number for short, is a non-negative integer whose decimal form contains the sub- string "13" and can be divided by 13. For example, 130 and 2613 are wqb-numbers, but 143 and 2639 are not. Your task is to calculate
how many wqb-numbers from 1 to n for a given integer n.
Input
Process till EOF. In each line, there is one positive integer n(1 <= n <= 1000000000).
Output
Print each answer in a single line.
Sample Input
13 100 200 1000
Sample Output
1 1 2 2
Author
wqb0039
Source
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#include<cstdio> #include<cstring> #include<iostream> #define FOR(i,a,b) for(int i=a;i<=b;++i) #define clr(f,z) memset(f,z,sizeof(f)) using namespace std; int dp[15][10][15][2];//位数,最后一个数,模剩数,是否有13 int bit[15],pos; int DP(int pp,int ee,int mod,bool has,bool big) { if(pp==0)return (mod==0&&has); if(big&&dp[pp][ee][mod][has]!=-1) return dp[pp][ee][mod][has]; int ret=0; int kn=big?9:bit[pp]; FOR(i,0,kn) { ret+=DP(pp-1,i,(mod*10+i)%13,has||(ee==1&&i==3),big||(bit[pp]!=i)); } if(big)dp[pp][ee][mod][has]=ret; return ret; } int get(int x) { pos=0; while(x) { bit[++pos]=x%10;x/=10; } clr(dp,-1); return DP(pos,0,0,0,0); } int main() { int n; while(cin>>n) { cout<<get(n)<<endl; } }
The article write by nealgavin