Given a string S, consisting of only 3 characters ‘A‘, ‘C‘, or ‘?‘. ‘A’ represents anti-clockwise movement, ‘C’ represents clockwise movement, and ‘?’ any movement, the task is to find the maximum distance you can travel in any of the directions from the initial position.
Examples:
Input: S = “AC?C”
Output: 2Input: S = “?C??CAC??”
Output: 7Input: S = “ACCA?C???”
Output: 5
Approach: This can be solved with the following idea:
The idea is to keep track of the number of ‘A’s and ‘C’s encountered so far using two variables currA and currC. Whenever an ‘A’ is encountered, currA will be incremented and currC will be decremented, and vice versa when a ‘C’ is encountered. If a ‘?’ is encountered, both currA and currC will be incremented. we will also keep track of the maximum difference between currA and currC encountered so far, using two variables maxA and maxC. In the end, the code returns the maximum of maxA and maxC as the result.
Steps involved in the implementation of code:
- Define a function named maxDistance that takes a string as input and returns an integer. The purpose of this function is to find the maximum distance between the number of ‘A’s and ‘C’s in the given string.
- Inside the function, initialize four integer variables currA, currC, maxA, and maxC to zero. currA and currC will be used to keep track of the number of ‘A’s and ‘C’s encountered so far, respectively, while maxA and maxC will be used to keep track of the maximum difference between ‘A’s and ‘C’s and ‘C’s and ‘A’s encountered so far, respectively.
- Use a for loop to iterate through each character in the input string.
-
Inside the for loop, use if-else statements to handle the following cases:
- If the current character is ‘A’, increment currA and decrement currC.
- If the current character is ‘C’, increment currC and decrement currA.
- If the current character is neither ‘A’ nor ‘C’ (i.e., ‘?’), increment both currA and currC.
- After updating currA and currC, use the max function to update maxA and maxC, respectively.
- Finally, outside the for loop, return the maximum of maxA and maxC as the output of the function.
Below is the implementation of the code:
C++
// C++ code for the above approach#include <iostream>#include <string>using namespace std;
// Function to find the maximum distance// between the number of 'A's and 'C's// in a stringint maximumdistance(string str)
{ int N = str.size();
int currA = 0;
int currC = 0;
int maxA = 0;
int maxC = 0;
for (int i = 0; i < N; i++) {
// If the current character is 'A'
if (str[i] == 'A') {
// Increment the number of
// 'A's encountered so far
currA++;
// Decrement the number of
// 'C's encountered so far
currC--;
}
// If the current character
// is 'C'
else if (str[i] == 'C') {
// Increment the number of
// 'C's encountered so far
currC++;
// Decrement the number of
// 'A's encountered so far
currA--;
}
// If the current character is
// neither 'A' nor 'C' (i.e., '?')
else {
// Increment the number of
// 'C's encountered so far
currC++;
// Increment the number of
// 'A's encountered so far
currA++;
}
// Update maxA if currA is
// greater than maxA
maxA = max(maxA, currA);
// Update maxC if currC is
// greater than maxC
maxC = max(maxC, currC);
}
return max(maxA, maxC);
}// Driver codeint main()
{ string Str = "A?ACAC??A";
// Function call
cout << maximumdistance(Str);
return 0;
} |
Java
// Java code for the above approachimport java.io.*;
import java.util.*;
class GFG {
// Function to find the maximum distance between the
// number of 'A's and 'C's in a string
static int maximumdistance(String str)
{
int N = str.length();
int currA = 0;
int currC = 0;
int maxA = 0;
int maxC = 0;
for (int i = 0; i < N; i++) {
// If the current character is 'A'
if (str.charAt(i) == 'A') {
// Increment the number of 'A's encountered
// so far
currA++;
// Decrement the number of 'C's encountered
// so far
currC--;
}
// If the current character is 'C'
else if (str.charAt(i) == 'C') {
// Increment the number of 'C's encountered
// so far
currC++;
// Decrement the number of 'A's encountered
// so far
currA--;
}
// If the current character is neither 'A' nor
// 'C' (i.e., '?')
else {
// Increment the number of 'C's encountered
// so far
currC++;
// Increment the number of 'A's encountered
// so far
currA++;
}
// Update maxA if currA is greater than maxA
maxA = Math.max(maxA, currA);
// Update maxC if currC is greater than maxC
maxC = Math.max(maxC, currC);
}
return Math.max(maxA, maxC);
}
public static void main(String[] args)
{
String Str = "A?ACAC??A";
// Function call
System.out.println(maximumdistance(Str));
}
}// This code is contributed by karthik. |
Python3
# Function to find the maximum distance# between the number of 'A's and 'C's# in a stringdef maximumdistance(s: str) -> int:
N = len(s)
currA = 0
currC = 0
maxA = 0
maxC = 0
for i in range(N):
# If the current character is 'A'
if s[i] == 'A':
# Increment the number of 'A's encountered so far
currA += 1
# Decrement the number of 'C's encountered so far
currC -= 1
# If the current character is 'C'
elif s[i] == 'C':
# Increment the number of 'C's encountered so far
currC += 1
# Decrement the number of 'A's encountered so far
currA -= 1
# If the current character is neither 'A' nor 'C' (i.e., '?')
else:
# Increment the number of 'C's encountered so far
currC += 1
# Increment the number of 'A's encountered so far
currA += 1
# Update maxA if currA is greater than maxA
maxA = max(maxA, currA)
# Update maxC if currC is greater than maxC
maxC = max(maxC, currC)
return max(maxA, maxC)
# Drive codeif __name__ == '__main__':
Str = "A?ACAC??A"
# Function call
print(maximumdistance(Str))
# This code is contributed by Nikhil Saini
|
C#
// C# code for the above approachusing System;
class GFG {
// Function to find the maximum distance between the
// number of 'A's and 'C's in a string
static int maximumdistance(string str)
{
int N = str.Length;
int currA = 0;
int currC = 0;
int maxA = 0;
int maxC = 0;
for (int i = 0; i < N; i++) {
// If the current character is 'A'
if (str[i] == 'A') {
// Increment the number of 'A's encountered
// so far
currA++;
// Decrement the number of 'C's encountered
// so far
currC--;
}
// If the current character is 'C'
else if (str[i] == 'C') {
// Increment the number of 'C's encountered
// so far
currC++;
// Decrement the number of 'A's encountered
// so far
currA--;
}
// If the current character is neither 'A' nor
// 'C' (i.e., '?')
else {
// Increment the number of 'C's encountered
// so far
currC++;
// Increment the number of 'A's encountered
// so far
currA++;
}
// Update maxA if currA is greater than maxA
maxA = Math.Max(maxA, currA);
// Update maxC if currC is greater than maxC
maxC = Math.Max(maxC, currC);
}
return Math.Max(maxA, maxC);
}
public static void Main()
{
string Str = "A?ACAC??A";
// Function call
Console.WriteLine(maximumdistance(Str));
}
}// This code is contributed by Vaibhav Nandan |
Javascript
// Function to find the maximum distance// between the number of 'A's and 'C's// in a stringfunction maximumdistance(str) {
let N = str.length;
let currA = 0;
let currC = 0;
let maxA = 0;
let maxC = 0;
for (let i = 0; i < N; i++) {
// If the current character is 'A'
if (str[i] === 'A') {
// Increment the number of
// 'A's encountered so far
currA++;
// Decrement the number of
// 'C's encountered so far
currC--;
}
// If the current character
// is 'C'
else if (str[i] === 'C') {
// Increment the number of
// 'C's encountered so far
currC++;
// Decrement the number of
// 'A's encountered so far
currA--;
}
// If the current character is
// neither 'A' nor 'C' (i.e., '?')
else {
// Increment the number of
// 'C's encountered so far
currC++;
// Increment the number of
// 'A's encountered so far
currA++;
}
// Update maxA if currA is
// greater than maxA
maxA = Math.max(maxA, currA);
// Update maxC if currC is
// greater than maxC
maxC = Math.max(maxC, currC);
}
return Math.max(maxA, maxC);
}// Driver codelet Str = "A?ACAC??A";
console.log(maximumdistance(Str)); |
Output
5
Time Complexity: O(N)
Auxiliary Space: O(1)
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