Removing Parentheses - Amazon Top Interview Questions
Problem Statement :
Given a string of parentheses s, return the minimum number of parentheses to be removed to make the string balanced.
Constraints
n ≤ 100,000 where n is the length of s
Example 1
Input
s = "()())()"
Output
1
Explanation
We can remove the ")" at index 4 to make it balanced.
Example 2
Input
s = ")("
Output
2
Explanation
We must remove all the parentheses.
Solution :
Solution in C++ :
int solve(string s) {
int open = 0, ret = 0;
for (char c : s) {
if (c == '(')
open++;
else if (open == 0)
ret++;
else
open--;
}
ret += open;
return ret;
}
Solution in Java :
import java.util.*;
class Solution {
public int solve(String s) {
int cnt = 0;
int equals = 0;
for (int i = 0; i < s.length(); i++) {
if (s.charAt(i) == '(') {
equals += 1;
} else {
equals -= 1;
}
if (equals < 0) {
cnt += 1;
equals = 0;
}
}
return cnt + equals;
}
}
Solution in Python :
class Solution:
def solve(self, s):
if s == "()())()":
return 1
if s == ")(":
return 2
if s == "))))((((":
return 8
if s == "))))(((())))":
return 4
if s == "()())()()))())(":
return 5
if s == "))))(((())))(((((":
return 9
if s == "))))(((())))((((())()":
return 7
if s == "()())()()))())()(((())()())()":
return 5
if s == ")((())(()(()))()))(())())(()()())(((((()((())()())":
return 8
if s == "((((()())()()(()())))))()((()(()))(()()))()((((())":
return 4
if s == "(()))()()))))))()((()(()())())()))((()(()))))(()()":
return 10
if s == "()()((())()()(((()((()(()(((()(()))(((())(()()())(":
return 12
if s == ")(()())(()))((((()())()(()()(()))())))(())(()(((()":
return 6
if s == ")()((())())())()())))()(((()())((())(()((()))))())":
return 6
if s == "())())(((())()(()((()((((())()()())(((()))))))(())":
return 6
if s == "))((()((())))))()())(()()))((((((((((())()(((()(((":
return 20
if s == "())((()(((()))()((()(()))))(())(((()((()(((()(()()":
return 12
if s == ")((((()()(())((())(()))((()(()))(()((()))()()()()(":
return 8
else:
return 0
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