hdu 2044(递推)

#include <iostream>
#include <cstdio>

using namespace std;

__int64 dp[55][55];

int main()
{
    for( int i = 1; i < 52; i++ )
        dp[i][i] = dp[i][i+1] = 1;

    int a, b;

    for( int i = 1; i <= 50; i++ )
        for( int j = i + 2; j <= 50; j++ )
        dp[i][j] = dp[i][j-1] + dp[i][j-2];
    int cas;
    scanf( "%d", &cas );
    while( cas-- )
    {
        scanf( "%d%d", &a, &b );
        printf( "%I64d\n", dp[a][b] );
    }
    return 0;

}