실버2 : 동적계획법 문제이다. Code // // main.cpp // algorithm_prac // // Created by 최완식 on 2021/04/05. // #include <iostream> using namespace std; int dp[101][101][101] = {0,}; int w(int a, int b, int c){ if (dp[a+50][b+50][c+50] != 0) { return dp[a+50][b+50][c+50]; } if (a <= 0 || b <= 0 || c <= 0) { dp[a+50][b+50][c+50] = 1; return dp[a+50][b+50][c+50]; } if (a > 20 || b > 20 || c > 20) { dp[a+50][b+50][c+50] = w(20, 20, 20); return dp[a+50][b+50][c+50]; } if (a < b && b < c) { dp[a+50][b+50][c+50] = w(a, b, c-1) + w(a, b-1, c-1) - w(a, b-1, c); return dp[a+50][b+50][c+50]; } dp[a+50][b+50][c+50] = w(a-1, b, c) + w(a-1, b-1, c) + w(a-1, b, c-1) - w(a-1, b-1, c-1); return dp[a+50][b+50][c+50]; } int main(){ ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL); int a, b, c; while (true) { cin >> a >> b >> c; if (a == -1 && b == -1 && c == -1) break; cout << "w(" << a << ", " << b << ", " << c << ") = " << w(a, b, c) << '\n'; } return 0; } } Reference 백준(9184번) - 신나는 함수 실행