multiple inputs by user dynamically at runtime

2019-04-15 05:09发布

问题:

How can we take multiple number of integer inputs by user choice in c in runtime. Here the first line of the input is the number of test cases. Then I am calculating the sum of the input numbers in this case.

The test case :

Input

3
1 6 7
2 7 3 4
2 1

Output:

14
16
3

Can we modify scanf() in this way so it can process this dynamic inputs.

I can't take the line as a string input and then split them into numbers.

Can we use the space and \n both to decide the numbers as we do to take strings as input as an example: scanf("%[^\n]",&str);

回答1:

The answer was provided by BLUEPIXY by his nice code. Here we will consider inputs as a pair.

Either it will be a pair of number and space or it will be a pair of number and newline character.

Example: 2 3 4

So in this input we take as pairs, like - '2', '3' and '4\n'. When we encounter a \n we stop the infinite loop. Here the code goes:

#include <stdio.h>

int main(void){
    int n;

    scanf("%d", &n);
    while(n--){
        int v, sum = 0;
        while(1){
            char ch = 0;
            scanf("%d%c", &v, &ch);
            sum += v;
            if(ch == '\n' || ch == 0)
                break;
        }
        printf("%d\n", sum);
    }

    return 0;
}

Inputs:

3
1 6 7
2 7 3 4
2 1

Output:

14
16
3