CC_1_2

ReverseString.java

// Cracking the Coding Interview
// 1.2 Implement a function void reverse(char* str) in C or C++ which reverses a null-terminated string.

#include <assert.h>
#include <iostream>
void reverse(char* str) {
	int len = 0;
	char *cur = str;
	char tmp = ' ';
	if (cur == NULL) return;
	while(*cur != '\0') {
		cur++;
		len++;
	}
	for(int i = 0; i < len/2; i++) {
		tmp = str[i];
		str[i] = str[len-i-1];
		str[len-i-1] = tmp;
	}
	return;
}
bool arrayCompare(char *str1, char *str2) {
	if (str1 == NULL && str2 == NULL) return 1;
	if (str1 == NULL || str2 == NULL || sizeof(*str1) != sizeof(*str2)) return 0;
	int len = sizeof(*str1);
	for(int i = 0; i<len; i++) {
		if (str1[i] != str2[i]) {
			return 0;
		}
	}
	return 1;
}
int main() {
	char test1[] = "Hello";
	char rtest1[] = "olleH";
	char test2[] = "";
	char test3[] = "Hell";
	char rtest3[] = "lleH";
	char *test4 = NULL;
	char test5[] = "\0";
	char test6[] = " ";
	reverse(test1);
	reverse(test2);
	reverse(test3);
	reverse(test4);
	reverse(test5);
	reverse(test6);

	assert(arrayCompare(test1, rtest1));
	assert(arrayCompare(test2, test2));
	assert(arrayCompare(test3, rtest3));
	assert(arrayCompare(test4, test4));
	assert(arrayCompare(test5, test5));
	assert(arrayCompare(test6, test6));
	std::cout<<"Tests passed"<<std::endl;
}