[codility] FrogRiverOne

[문제]

 

[답안작성]

class Solution {
    public int solution(int X, int[] A) {
        
        boolean[] isSuccess = new boolean[X];
        
        int point = 0;
        for( int i = 0; i < A.length; i++ ) {
            
            if( A[i] <= X ) {
                
                if( !isSuccess[ A[i] - 1 ] ) {
                    ++point;
                    isSuccess[ A[i] - 1 ] = true;
                }
                
            }
            
            if( point == X ) {
                return i;
            }
            
        }
        
        return -1;
        
    }
}