New update is available. Click here to update.

Solve problems & track your progress

Checkout your overall progress in every topic here

Become

Sensei

in DSA topics

Open the topic and solve more problems associated with it to improve your skills

Check out the skill meter for every topic

See how many problems you are left with to solve for cracking any stage. Score more than zero to get your progress counted.

Problem

Submissions

Implement strStr()

Contributed by

Shivam

Medium

0/80

Avg time to solve 25 mins

Success Rate 70 %

4 upvotes

Problem Statement

You are given two strings A and B. Find the index of the first occurrence of A in B. If A is not present in B, then return -1.

For Example:

A = “bc”, B = “abcddbc”.
String “A” is present at index 1, and 5(0-based index), but we will return 1 as it is the first occurrence of “A” in string “B”.

Follow Up:

Can you solve this in linear time and space complexity?

Detailed explanation ( Input/output format, Notes, Constraints, Images )

Input format:

The first line contains an integer 'T' which denotes the number of test cases or queries to be run. Then, the T test cases follow.

The first and only line of each test case contains two strings A and B, separated by a single space.

Output format:

For each test case, print the index of the first occurrence of A in B, if string A is not present in string B then print -1.

Note:

You do not need to print anything. It has already been taken care of. Just implement the given function.

Constraints:

1 <= T <= 100
1 <= |A|, |B| <= 5 * 10^4 

Time limit: 1 second

Sample Input 1:

2
ninjas codingninjas
code codingninjas

Sample Output 1:

6
-1

Explanation For Sample Input 1:

For the first test case, “ninjas” is present at the 6th index of “codingninjas”.

For the second test case, “code” is not present in “codingninjas”.

Sample Input 2:

2
e add
en engagement

Sample output 2:

-1
0

Auto

Console