First category  

 #include<stdio.h

int main()
{
    int n, k;
    int i;
    scanf("%d", &n);

//i Is the number of rows
    for (i = 1; i <= n; i++)
    {

//k Represents the number of spaces , Because the initial number is in the middle , So the output space should be the input number n- Number of rows i
        for (k = 1; k <=n-i; k++)
        {
            printf(" ");

        }

//j Represents the number of outputs with the same number , Obviously j So 2i-1 Ascending downward , And each line ,j++, until j greater than 2*i-1, Jump out of loop
        for (int j=0;j<2*i-1;j++)
        {

// The final output is (i-1)%10 Because the maximum number is 9, When entered n greater than 9 Hour , take n right 10 Remainder of
            printf("%d", (i-1)%10);
        }
        printf("\n");
        }

    return 0;
}

                                                          Second category

 

#include<stdio.h>
int main()
{
    int i, a, b, c;
    scanf("%d", &a);

//b Number of rows representing output ;
    for (b = 1; b <= a; b++)
    {

//i Represents the number of spaces output per line
        for (i = 1; i <= a - b; i++)printf(" ");

//c Represents the number of outputs per line ,(b-1) Number representing the first item ,(((b - 1) % 10) + c - 1) % 10); Represents the maximum number of outputs , And decrease in turn on both sides of the maximum number
        for (c = 1; c <= 2 * b - 1; c++) printf("%d", (((b - 1) % 10) + c -
1) % 10);

        printf("\n");
    }

    return 0;
}
                                                Third category

  Special attention should be paid when the value entered is greater than 26 Hour , The return value required for output is A, And the output is of string type

int main()
{
    int n;
    int b, c, i, d;
    scanf("%d", &n);
    d = 'A';
    for (b = 1; b <= n; b++)
    {
        for (i = 1; i <= n - b; i++)
        {
            printf(" ");
        }

Output value , Because it is a string type , So %c, And d Is a representative string 'A', So we need to d Put it outside (( b - 1)%26)) Because when the n greater than 26 Hour , Output to be reset to A

        for (c = 0; c < 2 * b - 1; c++)
        {
            printf("%c", d+(( b - 1)%26));
        }
        printf("\n");
    }

    return 0;
}

                                                          Fourth category

 

#include<stdio.h>
int main()
{
    int n ;
    int b, c, i, d, e;
    scanf("%d", &n);
    d = 'A';
    for (b = 1; b <=n; b++)
    {
        for (i = 1; i <= n - b; i++)
        {
            printf(" ");
        }
        for (c = 0; c < b; c++)
        {
            printf("%c", d + c);
        }
        if (b > 1)
        {

// When the number of rows is greater than one , character A plus e Value of
            for (e = b - 2; e >= 0; e--)
                printf("%c", d + e);
        }

        printf("\n");
    }

    return 0;
}

  It's really not easy to write and summarize , I hope you will support me in the future , I hope to surprise you in the future creation !

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