C++ Exercises: Sum of all positive integers in a sentence

Last update on August 11 2025 12:56:57 (UTC/GMT +8 hours)

Sum Positive Integers in Text

Write a C++ program to sum all positive integers in a sentence.
Sample string: There are 12 chairs, 15 desks, 1 blackboard and 2 fans.
Output: 30

Sample Solution:

C++ Code :

#include <bits/stdc++.h> // Includes most commonly used headers
using namespace std;

int main() {
    string str1; // Declare a string variable to store input

    int sum_num = 0, num; // Initialize variables to store the sum of numbers and individual numbers

    // Continuously read input lines until EOF
    while (getline(cin, str1)) {
        // Loop through each character in the string
        for (int i = 0; i < (int)str1.size(); i++) {
            if (isdigit(str1[i])) continue; // If the character is a digit, continue to the next character
            else {
                str1[i] = ' '; // Replace non-digit characters with space
            }
        }

        stringstream abc(str1); // Create a stringstream object 'abc' from the modified string

        // Extract integers from the stringstream and add them to sum_num
        while (abc >> num) {
            sum_num += num; // Add each extracted integer to the sum
        }
    }

    // Output the total sum of positive integers
    cout << "Sum of all positive integers: " << sum_num << endl;
    return 0;
}

Sample Output:

Input number: 12 chairs, 15 desks, 1 blackboard and 2 fans 
Sum of all positive integers: 30

Flowchart:

For more Practice: Solve these Related Problems:

Write a C++ program to parse a sentence, extract all positive integers, and then sum them without using regular expressions.
Write a C++ program that reads a text string, identifies all numeric substrings, and sums only those that represent positive integers.
Write a C++ program to scan through a given sentence, convert found numbers to integers, and compute the sum of all positive values.
Write a C++ program that processes a text containing mixed characters, extracts positive integers, and displays their cumulative sum.

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C++ Code Editor:

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