学步园

You are not necessary to keep the original order or positive integers or negative integers.

Given [-1, -2, -3, 4, 5, 6], after re-range, it will be [-1, 5, -2, 4, -3, 6] or any other legal answer.

Do it in-place and without extra memory.

看了网上的一些解法，是很巧妙，但是编程起来感觉没自己的这个更清晰些！分享下咯

class Solution {
    /**
     * @param A: An integer array.
     * @return an integer array
     */
    public int[] rerange(int[] A) {
        if(A==null || A.length<=1)
            return A;
        
        int s = 0;
        int p1 = -1;
        int p2 = -1;
        for(int i=0;i<A.length;i++){
            if(p1 == -1 && A[i] > 0)
                p1 = i;
            if(p1 == -1 && A[i] < 0)
                p2 = i;
            s += A[i] > 0?1:-1;
        }
        if(s<0)
            p1 = p2;
            
        int tmp = A[0];
        A[0] = A[p1];
        A[p1] = tmp;
        
        for(int i=1;i<A.length;i++){
            int j=i;
            while(j<A.length && A[j] * A[i-1]>0)
                j++;
            if(j>i && j<A.length){
                tmp = A[i];
                A[i] = A[j];
                A[j] = tmp;
            }
        }
        return A;
   }
}