UVA 12063（dp记忆化）

标签：dp   动态规划   记忆化搜索   

UVA - 12063

Submit Status

Description

Binary numbers and their pattern of bits are always very interesting to computer programmers. In this problem you need to count the number of positive binary numbers that have the following properties:

• The numbers are exactly N bits wide and they have no leading zeros.
• The frequency of zeros and ones are equal.
• The numbers are multiples of K.

Input 

The input file contains several test cases. The first line of the input gives you the number of test cases, T ( 1T100). Then T test cases will follow, each in one line. The input for each test case consists of two integers, N ( 1N64) and K ( 0K100).

Output 

For each set of input print the test case number first. Then print the number of binary numbers that have the property that we mentioned.

Sample Input 

5
6 3
6 4
6 2
26 3
64 2

Sample Output 

Case 1: 1
Case 2: 3
Case 3: 6
Case 4: 1662453
Case 5: 465428353255261088

Illustration: Here‘s a table showing the possible numbers for some of the sample test cases:

6 3	6 4	6 2
101010	111000	111000
	110100	110100
	101100	101100
		110010
		101010
		100110

Source

Submit Status

求长度为n的串(不含前导0)，0的个数和1的个数相等且是k的倍数的个数。

#include<bits/stdc++.h>
#define foreach(it,v) for(__typeof((v).begin()) it = (v).begin(); it != (v).end(); ++it)
using namespace std;
typedef long long ll;
ll dp[40][40][100];
int n,k,tot;
ll d(int ones,int zeros,int mod)
{
    ll & res = dp[ones][zeros][mod];
    if(res!=-1)return res;
    if(ones==tot&&zeros==tot) return res = (mod==0);
    if(ones==tot)return res = d(ones,zeros+1,(mod<<1)%k);
    if(zeros==tot)return res = d(ones+1,zeros,(mod<<1|1)%k);
    return res = d(ones+1,zeros,(mod<<1|1)%k) + d(ones,zeros+1,(mod<<1)%k);
}
int main()
{
    int T;
    scanf("%d",&T);
    for(int cas = 1; cas <= T; ++cas) {
        memset(dp,-1,sizeof dp);
        scanf("%d%d",&n,&k);
        ll res = 0;
        tot = n>>1;
        if((n&1)==0&&k)res = d(1,0,1);
        printf("Case %d: %lld\n", cas,res);
    }
    return 0;
}

UVA 12063（dp记忆化）

标签：dp   动态规划   记忆化搜索   

原文地址：http://blog.csdn.net/acvcla/article/details/45546913