c - 如何删除c中每行后的最后一个空格？

Question

我必须打印出帕斯卡三角形，我的输出如下-

1
1 1
1 2 1

我的代码给出了正确的输出，但在每行之后打印了一个额外的空格。有人可以告诉我如何摆脱它。这是我的代码-

//pascal

#include <stdio.h>

void pascal(int rows)
{
    int num = 1, i, j;

    for (i = 0; i < rows; i++)
    {
        for (j = 0; j <= i; j++)
        {
            if (j == 0 || i == 0)
            {
                num = 1;
            }
            else
            {
                num = num * (i - j + 1) / j;
            }
            printf("%d ", num);
        }
        printf("\n");
    }
}

int main()
{
    int rows;
    printf("Please enter how many levels of Pascal's Triangle you would like to see: ");

    scanf("%d", &rows);

    pascal(rows);

    return 0;
}

Answer 1

一种方法是在数字前打印空格，并且仅在 j > 0 时打印:

#include <stdio.h>
void pascal(int rows) {
    int num = 1, i, j;

    for (i = 0; i < rows; i++) {
        for (j = 0; j <= i; j++) {            
            if (j == 0 || i == 0) {
                num = 1;
            } else {
                num = num * (i - j + 1) / j;
            }
            if (j > 0) putchar(' '); // conditionally print the space
            printf("%d", num);       // no space here
        }
        printf("\n");
    }
}

或者在循环之前打印第一个1:

void pascal(int rows) {
    int num = 1, i, j;

    for (i = 0; i < rows; i++) {
        putchar('1');                  // print the first 1 here
        for (j = 1; j <= i; j++) {     // and start the loop at 1
            if (i == 0) {              // only i needs to be checked here
                num = 1;
            } else {
                num = num * (i - j + 1) / j;
            }
            printf(" %d", num);        // space before the number
        }
        printf("\n");
    }
}