[백준] 11049 행렬 곱셈 순서 - Dynamic Programming / Java

• 문제 링크

11049번: 행렬 곱셈 순서

 

• 풀이 과정

 

• 풀이 코드

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.StringTokenizer;

public class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        StringTokenizer st;

        int n = Integer.parseInt(br.readLine());

        int[] arr = new int[n + 1];
        int[][] dp = new int[n + 1][n + 1];

        for (int i = 0; i < n; i++) {
            st = new StringTokenizer(br.readLine());
            arr[i] = Integer.parseInt(st.nextToken());
            arr[i + 1] = Integer.parseInt(st.nextToken());
        }

        for (int l = 1; l < n; l++) {
            for (int i = 1; i + l <= n; i++) {
                int j = i + l;
                dp[i][j] = Integer.MAX_VALUE;
                for (int k = i; k < j; k++)
                    dp[i][j] = Math.min(dp[i][j], dp[i][k] + dp[k + 1][j] + (arr[i - 1] * arr[k] * arr[j]));
            }
        }

        bw.write(String.valueOf(dp[1][n]));
        bw.flush();
    }

}