[프로그래머스] 파괴되지 않은 건물

https://school.programmers.co.kr/learn/courses/30/lessons/92344

프로그래머스

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class Solution {
   public int solution(int[][] board, int[][] skill) {
        int N = board.length;
        int M = board[0].length;
        
        int[][] newBoard = new int[N+1][M+1];
        
        for(int i=0; i<skill.length; i++) {
        	int type = skill[i][0];
        	int r1 = skill[i][1];
        	int c1 = skill[i][2];
        	int r2 = skill[i][3];
        	int c2 = skill[i][4];
        	int degree = skill[i][5] * (type == 1 ? -1 : 1);
        	
    		newBoard[r1][c1] += degree;
    		newBoard[r1][c2+1] -= degree;
    		newBoard[r2+1][c1] -= degree;
    		newBoard[r2+1][c2+1] += degree;
        	
        }
        
        // 열 누적합
        for(int i=0; i<N; i++) {
        	for(int j=1; j<M; j++) {
            	newBoard[i][j] += newBoard[i][j-1];
            }
        }
        
        // 행 누적합
        for(int j=0; j<M; j++) {
        	for(int i=1; i<N; i++) {
        		newBoard[i][j] += newBoard[i-1][j];
        	}
        }
        
        int answer = 0;
        
        for(int i=0; i<N; i++) {
        	for(int j=0; j<M; j++) {
        		board[i][j] += newBoard[i][j];
        		if(board[i][j] > 0) answer++;
        	}
        }
        
        System.out.println(answer);
        
        return answer;
    }
}