string_1.c

#include <stdio.h>
#include <string.h>

int cspn(char s1[], char s2[]);
int spn(char s1[], char s2[]);
char *rchr(char str[], char c);
char *chr(char str[], char c);

char *str(char str[], char sub[])
{
	int i = 0, j;

	while (sub[i] != '\0')
	{
		j = 0;
		while (str[j] != '\0')
		{
			if ((sub[i] == str[j]) && (str[j + 1] == sub[i + 1]))
				return &str[j];
			j++;
		}
		i++;
	}
	return NULL;
}
int main(void)
{
	char *p;
	int n;
	p = chr("kumar shanu", 'm');
	printf("%s\n", p);
	n = cspn("honor 9 lite", "akj");
	printf("%d\n", n);
	p = str("honor on lite", "hello");
	printf("%s\n", p);
}
char *chr(char str[], char c)
{
	int i = 0;
	while (str[i] != '\0')
	{
		if (str[i] == c)
			return &str[i];
		i++;
	}
	return NULL;
}
char *rchr(char str[], char c)
{
	int i, l;
	l = strlen(str);

	for (i = l - 1; i >= 0; i--)
	{
		if (str[i] == c)
			return &str[i];
	}
	return NULL;
}
int spn(char s1[], char s2[])
{
	int i = 0, j = 0, count = 0;
	while (s2[i] != '\0')
	{
		j = 0;
		while (s1[j] != '\0')
		{
			if (s1[j] == s2[i])
				count++;
			j++;
		}
		i++;
	}
	return count;
}
int cspn(char s1[], char s2[])
{
	int i = 0, j, count = 0;

	while (s1[i] != '\0')
	{
		j = 0;
		while (s2[j] != '\0')
		{
			if (s1[i] == s2[j])
				return count;
			j++;
		}
		i++;
		count++;
	}
	return count;
}