Count of substrings of a Binary string containing only 1s

Given a binary string of length N, we need to find out how many sub-strings of this string contains only 1s.

Examples:

Input: S = “0110111”
Output: 9
Explanation:
There are 9 substring with only 1’s characters.
“1” comes 5 times.
“11” comes 3 times.
“111” comes 1 time.

Input: S = “000”
Output: 0

Approach: The idea is to traverse the binary string and count the consecutive one’s in the string. Below is the illustration of the approach:

Traverse the given binary string from index 0 to length – 1
Count the number of consecutive “1” till index i.
For each new character str[i], there will be more substring with all character’s as “1”

Below is the implementation of the above approach:

C++

// C++ implementation to find  
// count of substring containing  
// only ones  
  
#include <bits/stdc++.h>  
using namespace std;  
  
// Function to find the total number  
// of substring having only ones  
int countOfSubstringWithOnlyOnes(string s)  
{  
    int res = 0, count = 0;  
    for (int i = 0; i < s.length(); i++) {  
    count = s[i] == '1' ? count + 1 : 0;  
    res = (res + count);  
    }  
    return res;  
}  
  
// Driver Code  
int main()  
{  
    string s = "0110111";  
    cout << countOfSubstringWithOnlyOnes(s)  
        << endl;  
    return 0;  
}  

Java

// Java implementation to find  
// count of substring containing  
// only ones  
class GFG{  
      
// Function to find the total number  
// of substring having only ones  
static int countOfSubstringWithOnlyOnes(String s)  
{  
    int res = 0, count = 0;  
    for(int i = 0; i < s.length(); i++)  
    {  
        count = s.charAt(i) == '1' ? count + 1 : 0;  
        res = (res + count);  
    }  
    return res;  
}  
  
// Driver code  
public static void main(String[] args)  
{  
    String s = "0110111";  
      
    System.out.println(countOfSubstringWithOnlyOnes(s));  
}  
}  
  
// This code is contributed by dewantipandeydp  

Python3

# Python3 implementation to find  
# count of substring containing  
# only ones  
  
# Function to find the total number  
# of substring having only ones  
def countOfSubstringWithOnlyOnes(s):  
  
    count = 0
    res = 0
      
    for i in range(0,len(s)):  
        if s[i] == '1':  
            count = count + 1
        else:  
            count = 0;  
              
        res = res + count  
              
    return res  
  
# Driver Code  
s = "0110111"
print(countOfSubstringWithOnlyOnes(s))  
  
# This code is contributed by jojo9911  

C#

// C# implementation to find count 
// of substring containing only ones  
using System; 
  
class GFG{  
      
// Function to find the total number  
// of substring having only ones  
static int countOfSubstringWithOnlyOnes(string s)  
{  
    int res = 0, count = 0;  
      
    for(int i = 0; i < s.Length; i++)  
    {  
        count = s[i] == '1' ? count + 1 : 0;  
        res = (res + count);  
    }  
    return res;  
}  
  
// Driver code  
public static void Main(string[] args)  
{  
    string s = "0110111";  
      
    Console.Write(countOfSubstringWithOnlyOnes(s));  
}  
}  
  
// This code is contributed by rutvik_56 

Output

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My Personal Notes

C++

Java

Python3

C#

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