Process from standard input line by line-CodePudding

Given problem like this: Find the min and max from a list of integers. There are T test cases, for each test, print no. of current test cases and the answer.

Input.txt file

3
3 4 5 1 2
100 22 3 500 60
18 1000 77 10 300

Output

Test case 1: Max :5, Min :1
Test case 2: Max :500, Min :3
Test case 3: Max :1000, Min :10

In C , how can I process only one line from standard input in each test case iteration. The code that I have tried is like this.

#include <iostream>
#include <iterator>
#include <algorithm>


using namespace std;

int main() {
   
   freopen("input.txt","r",stdin);
   int T;
   cin>>T;

   for(int i=1; i<=T;   i) {
        vector<int> arrayInt;
        int n;

        //Should only process one line for each test case
        while(cin>>n) {
            arrayInt.push_back(n);
        }

        int max = *max_element(arrayInt.begin(), arrayInt.end());
        int min = *min_element(arrayInt.begin(), arrayInt.end());
        cout<<"Test case " << i << ": Max :" << max << ", Min :"<< min << "\n";
   }

}

Output that I got when I run it on the command line

Test case 1: Max :1000, Min :1

Please help me to fix my code. Thanks in advance for the answers.

CodePudding user response：

In C , how can I process only one line from standard input in each test case iteration.

std::getline reads until it finds a line break (thats the default, other delmiters can be used).

Replace

    while(cin>>n) {
        arrayInt.push_back(n);
    }

With

    std::string line;
    std::getline(std::cin, line);
    std::istringstream linestream{line};       
    while(linestream >> n) {
        arrayInt.push_back(n);
    }

Also note that there is std::minmax_element which can get both min and max in a single pass.