[Record] Luogu test field _ process and recursive function _ p1028, record_p1028

[Record] Luogu test field _ process and recursive function _ p1028, record_p1028

First way:

First try:

1 # include <bits/stdc ++. h> 2 using namespace std; 3 int k = 1; 4 void add (int s) 5 {6 if (s <= 1 | s/2 <= 0) return; 7 for (int I = 1; I <= s/2; I ++) 8 {9 add (I); 10 k ++; 11} 12} 13 int main () 14 {15 int n; 16 cin> n; 17 add (n); 18 cout <k; 19}

Result:

Timeout.

Second way:

First try:

1 # include <bits/stdc ++. h> 2 using namespace std; 3 int a [10001]; 4 int main () 5 {6 int n; 7 cin> n; 8 a [0] = 1; 9 for (int I = 1; I <= n; I ++) 10 for (int j = 0; j <= I/2; j ++) 11 a [I] + = a [j]; 12 cout <a [n]; 13 14}

Result:

Correct.

Reflection:Second wayAn array is used to simulate each sub-number that meets the conditions, and the call is directly output, with little time complexity.