[codility_] PassingCars

app.codility.com/programmers/lessons/5-prefix_sums/passing_cars/

PassingCars coding task - Learn to Code - Codility

처음에 푼답 --> 40.. 퍼 --> 0일때 카운트도 넣어줘야 함.

// you can also use imports, for example:
// import java.util.*;

// you can write to stdout for debugging purposes, e.g.
// System.out.println("this is a debug message");

class Solution {
    public int solution(int[] A) {
    

        int iRet = 0 ;
        int iTempsWestCnt = 0 ;
        int []arrWest = new int[A.length];

        for(int i =A.length-1 ; i >= 0 ; i--)
        {
            if(A[i] == 1)
            {
                iTempsWestCnt++;
                arrWest[i] = iTempsWestCnt ; // 제거 
            }
            
            //arrWest[i] = iTempsWestCnt ;  추가 
        }

        for(int i =0 ; i < A.length-1; i++)
        {
            if(A[i] == 0)
            {

                iRet += arrWest[i+1];
                
                if(iRet > 1000000000)
                    return -1 ;
            }
        }

        return iRet ;
    }
}

class Solution {
    public int solution(int[] A) {
    

        int iRet = 0 ;
        int iTempsEestCnt = 0 ;
        for(int i = 0 ; i< A.length ; i++)
        {
            if(A[i] == 0)
                iTempsEestCnt++;
            else
                iRet += iTempsEestCnt ;

            if(iRet > 1000000000) return -1;
        }

        return iRet ;
    }
}