POJ 2193 Lenny's Lucky Lotto Lists(简单二维dp)

一道水题，竟然脑子抽筋比赛时没做出来啊。sad、、、以位数和结尾数字进行dp。

Lenny's Lucky Lotto Lists

Time Limit: 1000MS Memory Limit: 65536KTotal Submissions: 2068 Accepted: 881

Description

Lenny likes to play the game of lotto. In the lotto game, he picks a list of N unique numbers in the range from 1 to M. If his list matches the list of numbers that are drawn, he wins the big prize. 
Lenny has a scheme that he thinks is likely to be lucky. He likes to choose his list so that each number in it is at least twice as large as the one before it. So, for example, if N = 4 and M = 10, then the possible lucky lists Lenny could like are: 

1 2 4 8 
1 2 4 9 
1 2 4 10 
1 2 5 10

Thus Lenny has four lists from which to choose. 
Your job, given N and M, is to determine from how many lucky lists Lenny can choose. 

Input

There will be multiple cases to consider from input. The first input will be a number C (0 < C <= 50) indicating how many cases with which you will deal. Following this number will be pairs of integers giving values for N and M, in that order. You are guaranteed that 1 <= N <= 10, 1 <= M <= 2000, and N <= M. Each N M pair will occur on a line of its own. N and M will be separated by a single space.

Output

For each case display a line containing the case number (starting with 1 and increasing sequentially), the input values for N and M, and the number of lucky lists meeting Lenny's requirements. The desired format is illustrated in the sample shown below.

Sample Input

34 102 202 200

Sample Output

Case 1: n = 4, m = 10, # lists = 4Case 2: n = 2, m = 20, # lists = 100Case 3: n = 2, m = 200, # lists = 10000

#include <algorithm>#include <iostream>#include <stdlib.h>#include <string.h>#include <iomanip>#include <stdio.h>#include <string>#include <queue>#include <cmath>#include <stack>#include <map>#include <set>#define eps 1e-7#define M 1000100//#define LL __int64#define LL long long#define INF 0x3fffffff#define PI 3.1415926535898#define MOD 1000000007using namespace std;const int maxn = 2020;LL dp[12][maxn];int main(){    int T;    cin >>T;    for(int t = 1; t <= T; t++)    {        int n, m;        cin >>n>>m;        memset(dp, 0 , sizeof(dp));        for(int i = 0; i <= m; i++)            dp[1][i] = 1;        for(int i = 1; i <= n; i++)            for(int j = 1; j <= m; j++)                for(int k = j+1; k <= m; k++)                    if(k >= 2*j)                        dp[i][k] += dp[i-1][j];        LL sum = 0;        for(int i = 1 ;i <= m; i++)            sum += dp[n][i];        cout<<"Case "<<t<<": n = "<<n<<", m = "<<m<<", # lists = "<<sum<<endl;    }    return 0;}