80. 删除排序数组中的重复项 II - 0301

给定一个排序数组，你需要在原地删除重复出现的元素，使得每个元素最多出现两次，返回移除后数组的新长度。

// Remove Duplicates from Sorted Array II
-(NSInteger)removeElementInSortedArrayII:(NSMutableArray <NSNumber *> *)array
{
    NSInteger max = 2;
    if (array.count <= max) {
        return array.count;
    }
    NSInteger length = 0;
    NSInteger repeatCount = 0;
    for (int i=1; i<array.count; i++) {
        if (array[length].integerValue == array[i].integerValue) {
            if (repeatCount < 2) {
                repeatCount ++;
                array[++length] = array[i];
            }
        } else {
            array[++length] = array[i];
            repeatCount = 1;
        }
        NSLog(@"%@",array);
    }
    length ++;
    if (array.count > length) {
        [array removeObjectsInRange:NSMakeRange(length, array.count - length)];
    }
    NSLog(@"%@",array);
    return length;
}