#include <stdio.h>

int main()
{
    int i, j, rows;

    printf("行数: ");
    scanf("%d",&rows);

    for(i=1; i<=rows; ++i)
    {
        for(j=1; j<=i; ++j)
        {
            printf("* ");
        }
        printf("\n");
    }
    return 0;
}

*
* *
* * *
* * * *
* * * * *

#include <stdio.h>

int main()
{
    int i, j, rows;

    printf("行数: ");
    scanf("%d",&rows);

    for(i=1; i<=rows; ++i)
    {
        for(j=1; j<=i; ++j)
        {
            printf("%d ",j);
        }
        printf("\n");
    }
    return 0;
}

1
1 2
1 2 3
1 2 3 4
1 2 3 4 5

#include <stdio.h>
int main()
{
    int i, j;
    char input, alphabet = 'A';

    printf("输入大写字母: ");
    scanf("%c",&input);

    for(i=1; i <= (input-'A'+1); ++i)
    {
        for(j=1;j<=i;++j)
        {
            printf("%c", alphabet);
        }
        ++alphabet;

        printf("\n");
    }
    return 0;
}

A
B B
C C C
D D D D
E E E E E

#include <stdio.h>
int main()
{
    int i, j, rows;

    printf("行数: ");
    scanf("%d",&rows);

    for(i=rows; i>=1; --i)
    {
        for(j=1; j<=i; ++j)
        {
            printf("* ");
        }
        printf("\n");
    }

    return 0;
}

* * * * *
* * * *
* * * 
* *
*

#include <stdio.h>
int main()
{
    int i, j, rows;

    printf("行数: ");
    scanf("%d",&rows);

    for(i=rows; i>=1; --i)
    {
        for(j=1; j<=i; ++j)
        {
            printf("%d ",j);
        }
        printf("\n");
    }

    return 0;
}

1 2 3 4 5
1 2 3 4 
1 2 3
1 2
1

#include <stdio.h>
int main()
{
    int i, space, rows, k=0;

    printf("Enter number of rows: ");
    scanf("%d",&rows);

    for(i=1; i<=rows; ++i, k=0)
    {
        for(space=1; space<=rows-i; ++space)
        {
            printf("  ");
        }

        while(k != 2*i-1)
        {
            printf("* ");
            ++k;
        }

        printf("\n");
    }

    return 0;
}

        *
      * * *
    * * * * *
  * * * * * * *
* * * * * * * * *

#include <stdio.h>
int main()
{
    int i, space, rows, k=0, count = 0, count1 = 0;

    printf("行数: ");
    scanf("%d",&rows);

    for(i=1; i<=rows; ++i)
    {
        for(space=1; space <= rows-i; ++space)
        {
            printf("  ");
            ++count;
        }

        while(k != 2*i-1)
        {
            if (count <= rows-1)
            {
                printf("%d ", i+k);
                ++count;
            }
            else
            {
                ++count1;
                printf("%d ", (i+k-2*count1));
            }
            ++k;
        }
        count1 = count = k = 0;

        printf("\n");
    }
    return 0;
}

        1
      2 3 2
    3 4 5 4 3
  4 5 6 7 6 5 4
5 6 7 8 9 8 7 6 5

#include<stdio.h>
int main()
{
    int rows, i, j, space;

    printf("行数: ");
    scanf("%d",&rows);

    for(i=rows; i>=1; --i)
    {
        for(space=0; space < rows-i; ++space)
            printf("  ");

        for(j=i; j <= 2*i-1; ++j)
            printf("* ");

        for(j=0; j < i-1; ++j)
            printf("* ");

        printf("\n");
    }

    return 0;
}

* * * * * * * * *
  * * * * * * *
    * * * * *
      * * *
        *

#include <stdio.h>
int main()
{
    int rows, coef = 1, space, i, j;

    printf("行数: ");
    scanf("%d",&rows);

    for(i=0; i<rows; i++)
    {
        for(space=1; space <= rows-i; space++)
            printf("  ");

        for(j=0; j <= i; j++)
        {
            if (j==0 || i==0)
                coef = 1;
            else
                coef = coef*(i-j+1)/j;

            printf("%4d", coef);
        }
        printf("\n");
    }

    return 0;
}

           1
         1   1
       1   2   1
     1   3   3    1
   1  4    6   4   1
 1  5   10   10  5   1

#include <stdio.h> 
#define N 10 
int main() 
{  
    int i,j,l; 
    for(i=1,j=1;i<=N;i++) 
    { 
        for(l=1;l<=i;l++,j++) 
            printf("%5d",j); 
        printf("\n"); 
    } 
    return 0; 
}

    1
    2    3
    4    5    6
    7    8    9   10
   11   12   13   14   15
   16   17   18   19   20   21
   22   23   24   25   26   27   28
   29   30   31   32   33   34   35   36
   37   38   39   40   41   42   43   44   45
   46   47   48   49   50   51   52   53   54   55