bbchu's note

// 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) {
        // write your code in Java SE 8
        
        if (A.length < 3) {
            return 0;
        }
        Arrays.sort(A);
        
        int start = 0;
        while (start < A.length) {
            if (A[start] > 0) {
                break;
            }
            start++;
        }
        
        if (start >= A.length) {
            return 0;
        }
        
        int result = 0;
        for (int i = 0; i < A.length-1; i++) {
            for (int j = (i+1); j < A.length-1; j++) {
                
                if ((long)A[i] + (long)A[j] > (long)A[j+1]) {
                    result = 1;
                    break;
                }
            }
            if (result == 1) {
                break;
            }
        }
        
        return result;
    }
}

// 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) {
        // write your code in Java SE 8
        
        if (A.length == 1) {
            return 0;
        }
        
        int start = 0;
        while (start < A.length) {
            if (A[start] == 0) {
                break;
            }
            start++;
        }
        
        if (start == A.length) {
            return 0;
        }
        
        int pCount = 0;
        int result = 0;
        for (int i = start; i < A.length; i++) {
            if (A[i] == 0) {
                pCount++;
            } else {
                result += pCount;
            }
            
            if (result > 1000000000) {
                result = -1;
                break;
            }
        }
            
        return result;
    }
}

// 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 X, int[] A) {
        // write your code in Java SE 8
        
        int[] positions = new int[X];
        int result = -1;
        int count = 0;
        int i;
        for (i = 0; i < A.length; i++) {
            int idx = A[i] - 1;
            if (idx < X) {
                if ( positions[idx] == 0 ) {
                    positions[idx]++;
                    count++;
                }
            }
            
            if (count == X) {
                result = i;
                break;
            }
        }
        
        return result;
    }
    
}