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Abhishek Chaudhary

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Truncate Sentence

A sentence is a list of words that are separated by a single space with no leading or trailing spaces. Each of the words consists of only uppercase and lowercase English letters (no punctuation).

• For example, `"Hello World"`, `"HELLO"`, and `"hello world hello world"` are all sentences.

You are given a sentence `s`​​​​​​ and an integer `k`​​​​​​. You want to truncate `s`​​​​​​ such that it contains only the first `k`​​​​​​ words. Return `s`​​​​​​ after truncating it.

Example 1:

Input: s = "Hello how are you Contestant", k = 4
Output: "Hello how are you"
Explanation:
The words in s are ["Hello", "how" "are", "you", "Contestant"].
The first 4 words are ["Hello", "how", "are", "you"].
Hence, you should return "Hello how are you".

Example 2:

Input: s = "What is the solution to this problem", k = 4
Output: "What is the solution"
Explanation:
The words in s are ["What", "is" "the", "solution", "to", "this", "problem"].
The first 4 words are ["What", "is", "the", "solution"].
Hence, you should return "What is the solution".

Example 3:

Input: s = "chopper is not a tanuki", k = 5
Output: "chopper is not a tanuki"

Constraints:

• `1 <= s.length <= 500`
• `k` is in the range `[1, the number of words in s]`.
• `s` consist of only lowercase and uppercase English letters and spaces.
• The words in `s` are separated by a single space.
• There are no leading or trailing spaces.

SOLUTION:

``````class Solution:
def truncateSentence(self, s: str, k: int) -> str:
n = len(s)
i = 0
ctr = 0
for i in range(n):
if s[i] == " ":
ctr += 1
if ctr == k:
return s[:i]
return s
``````