Geeksforgeeks

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Your task is to implement the function **strstr**. The function takes two strings as arguments **(s,x)** and locates the occurrence of the string** x** in the string **s**. The function returns and integer denoting the **first occurrence **of the string **x** in **s** (0 based indexing).

**Note: **You are not allowed to use inbuilt function.

**Example 1:**

**Input:
**s = GeeksForGeeks, x = Fr
**Output: **-1**
Explanation: **Fr is not present in the
string GeeksForGeeks as substring.**
**

**Example 2:**

**Input:
**s = GeeksForGeeks, x = For
**Output: **5**
Explanation: **For is present as substring
in GeeksForGeeks from index 5 (0 based
indexing).

**Your Task:**

You don't have to take any input. Just complete the **strstr() **function which takes two strings **str, target** as an input parameter. The function returns -1 if no match if found else it returns an integer denoting the first occurrence of the x in the string s.

**Expected Time Complexity:** O(|s|*|x|)

**Expected Auxiliary Space:** O(1)

**Note **: Try to solve the question in constant space complexity.

**Constraints:**

1 <= |s|,|x| <= 100

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Implement strstr

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