printTriangle with alphabets - c

Question

#include <stdio.h>
int inputNumber();
void printTriangle(int size, char ch[]);
int main()
{
char arr_char[] = {'a','e','i','o','u'};
int number;
number = inputNumber();
printTriangle(number,arr_char);
return 0;
}
int inputNumber()
{
int size;
printf("Input Size: ");
scanf("%d",&size);
printf("===\nTriangle Size is %d\n===\n",size);
return size;
}
void printTriangle(int size, char ch[5])
{
int i,j;
for(i=0;i<size;i++)
{
for(j=0;j<size;j++)
{
if(j <= 4)
{
printf("%s ",ch[j]);
}
if(j > 4 )
{
printf("# ");
}
}
}
}
This is what it supposed to look like. And I'm confused as what I did wrong because it only work with inputNumber but not with printTriangle. a e i o u # # # please go easy on me since I'm kinda new to this.

Answer 1

The segmentation fault is caused by an incorrect format string (%s should be %c). The output format doesn't match expectations as the inner loop condition is wrong and you need a newline after you print each line (after inner loop):
#include <stdio.h>
#define LEN 5
int inputNumber() {
int size;
printf("Input Size: ");
scanf("%d",&size);
printf("===\nTriangle Size is %d\n===\n",size);
return size;
}
void printTriangle(int size, char ch[]) {
for(int i = 0; i < size; i++) {
for(int j = 0; j <= i; j++) {
printf("%c ", j < LEN ? ch[j] : '#');
}
printf("\n");
}
}
int main() {
char arr_char[LEN] = {'a','e','i','o','u'};
int number;
number = inputNumber();
printTriangle(number,arr_char);
return 0;
}
Consider using the type unsigned instead of int as negative size, row (i) and column (j) doesn't make sense.
Here is an alternatively implementation of printTriangle() that does a bit of work upfront to generate the last row, then use a prefix of that last row to print all rows:
void printTriangle(unsigned size, char ch[]) {
// use malloc if size is large (say >4k),
// or you don't want to use a variable length array (VLA)
char str[2 * size];
for(unsigned column = 0; column < size; column++) {
str[2 * column] = column < LEN ? ch[column] : '#';
str[2 * column + 1] = ' ';
}
for(unsigned row = 0; row < size; row++) {
printf("%.*s\n", 2 * row + 1, str);
}
}