HDU 2044 一只小蜜蜂

Posted 2021-01-26 yanyiming10243247

经典线性DP Fabonacci

 1 #include <algorithm>
 2 #include <iostream>
 3 #include <cstring>
 4 #include <cstdio>
 5 #include <cctype>
 6 
 7 using namespace std;
 8 
 9 inline void read(long long &x)
10 {
11     int k = 1; x = 0;
12     char c = getchar();
13     while (!isdigit(c))
14         if (c == ‘-‘) k = - 1, c = getchar();
15         else c = getchar();
16     while (isdigit(c))
17         x = (x << 1) + (x << 3) + (c ^ 48),
18         c = getchar();
19     x *= k;
20 }
21 
22 long long T, a, b, dp[55], fir, las;
23 
24 int main()
25 {
26     read(T);
27     for (int plk = 1; plk <= T; ++plk)
28     {
29         read(a), read(b);
30         memset(dp, 0, sizeof(dp));
31         dp[0] = 0, dp[a] = 1;
32         for (int i = a + 1; i <= b; ++i)
33             dp[i] = dp[i - 1] + dp[i - 2]; 
34         printf("%lld
", dp[b]);
35     }
36     return 0;
37 }