P1025 数的划分 --dp,dfs

 1 #include 
 2 using i64 = long long;
 3 using namespace std;
 4 #define repk(i,s,t,k) for(int i = s; i <= t; i += k)
 5 #define rep(i,s,t) repk(i,s,t,1)
 6 #define perk(i,s,t,k) for(int i = s; i >= t; i -= k)
 7 #define per(i,s,t) perk(i,s,t,1)
 8 
 9 int f[201][7];
10 int main(){
11     std::ios::sync_with_stdio(false);
12     std::cin.tie(nullptr);
13     int n,k;
14     cin >> n >> k;
15     rep(i,1,n) f[i][1] = 1,f[i][0] = 1;
16     rep(i,2,k) f[1][i] = 0,f[0][i] = 0;
17     rep(i,2,n) rep(x,2,k) {
18         if(i > x) f[i][x] = f[i-1][x-1] + f[i-x][x];
19         else f[i][x] = f[i-1][x-1];
20     }
21     cout << f[n][k];
22     return 0;
23 }