34. 在排序数组中查找元素的第一个和最后一个位置（C语言）

笨办法，先找第一个等于target的位置，再找最后一个等于target的位置 

/**
 * Note: The returned array must be malloced, assume caller calls free().
 */
int* searchRange(int* nums, int numsSize, int target, int* returnSize){
    *returnSize=2;
    int *ret=malloc(2*4);
    int lo=0,hi=numsSize-1;
    int pre;
    pre=prefind(nums,target,lo,hi);
    int post;
    post=postfind(nums,target,lo,hi,numsSize);
    ret[0]=pre;
    ret[1]=post;
    return ret;
}
int prefind(int *nums,int target,int low,int high){
    
    while(low<=high){
        int mid=low+(high-low)/2;
        if(nums[mid]<target){
            low=mid+1;
        }else if(nums[mid]>target){
            high=mid-1;
        }else{
            if((mid==0)||(nums[mid-1]!=target))return mid;
            else high=mid-1;
        }
    }
    return -1;
}

int postfind(int *nums,int target,int low,int high,int numsSize){
    while(low<=high){
        int mid=low+(high-low)/2;
        if(nums[mid]<target){
            low=mid+1;
        }else if(nums[mid]>target){
            high=mid-1;
        }else{
            if((mid==numsSize-1)||(nums[mid+1]!=target))return mid;
            else low=mid+1;
        }
    }
    return -1;
}