[DP] 정수 삼각형

백준 1932 정수삼각형

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

public class Main {

    static int[][] triangle;
    static int N;
    static int[][] D;

    public static void main(String[] args) throws Exception {

        //N개의 정수를 배열로 받음
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = null;
        N = Integer.parseInt( br.readLine() );

        triangle = new int[N][N];
        D = new int[N][N];

        for(int i=0; i<N; i++) {
            st = new StringTokenizer(br.readLine());
            for(int j=0; j<i+1; j++) {
                triangle[i][j] = Integer.parseInt(st.nextToken());

                if(i==0) {
                    D[i][j] = triangle[0][0];
                    continue;
                }

                if(j==0) D[i][j] = triangle[i][j] +D[i-1][j];
                else D[i][j] = triangle[i][j] + Math.max( D[i-1][j-1] , D[i-1][j] );
            }
        }

        int max=0;
        for(int i=0; i<N; i++) {
            if(max<D[N-1][i]) max=D[N-1][i];
        }
        System.out.println( max );
    }

}