Given a binary string str of length N and two integers A and B such that 0 ? A < B < n. The task is to count the minimum number of operations on the string such that it gives 10A as remainder when divided by 10B. An operation means changing 1 to 0 or 0 to 1.
Examples:
Input: str = “1001011001”, A = 3, B = 6
Output: 2
The string after 2 operations is 1001001000.
1001001000 % 106 = 103Input: str = “11010100101”, A = 1, B = 5
Output: 3
Approach: In order for the number to give 10A as remainder when divided by 10B, the last B digits of the string has to be 0 except the digit at (A + 1)th position from the last which should be 1. Therefore, check the last B digits of the string for the above condition and increase the count by 1 for each mismatch of digit.
Below is the implementation of the above approach:
C++
// C++ implementation of the approach #include <bits/stdc++.h> using namespace std; // Function to return the minimum number // of operations on a binary string such that // it gives 10^A as remainder when divided by 10^B int findCount(string s, int n, int a, int b) { // Initialize result int res = 0; // Loop through last b digits for ( int i = 0; i < b; i++) { if (i == a) res += (s[n - i - 1] != '1' ); else res += (s[n - i - 1] != '0' ); } return res; } // Driver code int main() { string str = "1001011001" ; int N = str.size(); int A = 3, B = 6; cout << findCount(str, N, A, B); return 0; } |
Java
// Java implementation of the approach import java.util.*; class GFG { // Function to return the minimum number // of operations on a binary string such that // it gives 10^A as remainder when divided by 10^B static int findCount(String s, int n, int a, int b) { // Initialize result int res = 0 ; char []s1 = s.toCharArray(); // Loop through last b digits for ( int i = 0 ; i < b; i++) { if (i == a) { if (s1[n - i - 1 ] != '1' ) res += 1 ; } else { if (s1[n - i - 1 ] != '0' ) res += 1 ; } } return res; } // Driver code static public void main (String []args) { String str = "1001011001" ; int N = str.length() ; int A = 3 , B = 6 ; System.out.println(findCount(str, N, A, B)); } } // This code is contributed by ChitraNayal |
Python3
# Python 3 implementation of the approach # Function to return the minimum number # of operations on a binary string such that # it gives 10^A as remainder when divided by 10^B def findCount(s, n, a, b): # Initialize result res = 0 # Loop through last b digits for i in range (b): if (i = = a): res + = (s[n - i - 1 ] ! = '1' ) else : res + = (s[n - i - 1 ] ! = '0' ) return res # Driver code if __name__ = = '__main__' : str = "1001011001" N = len ( str ) A = 3 B = 6 print (findCount( str , N, A, B)) # This code is contributed by # Surendra_Gangwar |
C#
// C# implementation of the approach using System; class GFG { // Function to return the minimum number // of operations on a binary string such that // it gives 10^A as remainder when divided by 10^B static int findCount( string s, int n, int a, int b) { // Initialize result int res = 0; // Loop through last b digits for ( int i = 0; i < b; i++) { if (i == a) { if (s[n - i - 1] != '1' ) res += 1; } else { if (s[n - i - 1] != '0' ) res += 1 ; } } return res; } // Driver code static public void Main () { string str = "1001011001" ; int N = str.Length ; int A = 3, B = 6; Console.WriteLine(findCount(str, N, A, B)); } } // This code is contributed by AnkitRai01 |
Javascript
<script> // Javascript implementation of the approach // Function to return the minimum number // of operations on a binary string such that // it gives 10^A as remainder when divided by 10^B function findCount(s, n, a, b) { // Initialize result var res = 0; // Loop through last b digits for ( var i = 0; i < b; i++) { if (i == a) res += (s[n - i - 1] != '1' ); else res += (s[n - i - 1] != '0' ); } return res; } // Driver code var str = "1001011001" ; var N = str.length; var A = 3, B = 6; document.write(findCount(str, N, A, B)); // This code is contributed by itsok </script> |
2
Time Complexity: O(N )
Auxiliary Space: O(1)
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