Leetcode Find First and Last Position of Element in Sorted Array problem solution

YASH PAL,

In this Leetcode Find First and the Last Position of Element in Sorted Array problem solution we have Given an array of integers nums sorted in ascending order, find the starting and ending position of a given target value.

If the target is not found in the array, return [-1, -1]. You must write an algorithm with O(log n) runtime complexity.

Leetcode Find First and the Last Position of Element in Sorted Array problem solution

Problem solution in Python.

class Solution:
    def searchRange(self, nums, target):
        left = bisect.bisect_left(nums, target)
        if left == len(nums) or nums[left] != target:
            return [-1, -1]
        right = bisect.bisect_right(nums, target)
        return [left, right - 1]

Problem solution in Java.

class Solution {
    public int[] searchRange(int[] nums, int target) {
        int start = 0;
        int end = nums.length-1;
        int first =-1;
        while(start<=end){
            int mid = (start+end)/2;
            if(nums[mid]==target)first = mid;
            if(nums[mid]>=target)end = mid-1;
            else start =mid+1;
        }
        int last  = -1;
        start=0;end =nums.length-1;
        while(start<=end){
              int mid = (start+end)/2;
            if(nums[mid]==target)last = mid;
            if(nums[mid]>target)end = mid-1;
            else start =mid+1;
        }
        return new int[]{first,last};
    }
}

Problem solution in C++.

int bs(vector<int> &nums, int target, int left, int right) { // binary search
    while (left < right) {
        int mid = (right + left) / 2;
        if (nums[mid] == target && (mid == 0 || nums[mid - 1] != target))
            return mid;
        else if (nums[mid] >= target)
            right = mid;
        else
            left = mid + 1;
    }
    return left;
}
vector<int> searchRange(vector<int>& nums, int target) {
    int l = bs(nums, target, 0, nums.size());
    if (l == nums.size() || nums[l] != target)
        return {-1, -1};
    int r = bs(nums, target + 1, l, nums.size()) - 1;
    return {l, r};
}

Problem solution in C.

int* searchRange(int* nums, int numsSize, int target, int* returnSize){
    *returnSize=2;
    int * result=(int*)malloc(sizeof(int)*2);
    result[0]=-1;
    result[1]=-1;
    int start=-1;
    int end=-1;
    if(numsSize==0)
    {
        return result;
    }
    for(int i=0;i<numsSize;i++)
    {
        if(nums[i]==target)
        {
            start=i;
            break;
        }
    }
    for(int i=numsSize-1;i>=0;i--)
    {
        if(nums[i]==target)
        {
            end=i;
            break;
        }
    }
    result[0]=start;
    result[1]=end;
    return result;
}

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