//  模拟库函数strstr

#include <stdio.h>

#include <assert.h>

const char* my_strstr(const char *parent, const char *child)

{

	const char *pgo = parent;

	const char *cgo = child;

	const char *pgos = parent;

	assert(parent != NULL && child != NULL);

	if (!*child)

	{

		return NULL;

	}

	while (*pgo)

	{

		pgo = pgos;

		cgo = child;

		while (*pgo == *cgo && *pgo && *cgo)

		{

			pgo++;

			cgo++;

		}

		if (*cgo == '\0')

			return pgos;

		pgos++;

	}

	return NULL;

}

int main()

{

	printf("%s\n", my_strstr("hhhww", "hhww"));

	printf("%s\n", my_strstr("zhaoyaqian","aoya"));

	printf("%s\n", my_strstr("abc", "aefg"));

	return 0;

}