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

CareerCup 1.2.c

#include <stdio.h>
void swap(char* a, char* b);
void reverse(char* str);

int main(){
    char strArray[] = "1point3acres";
    printf("Before Reverse: %s\n", strArray);
    reverse(strArray);
    printf("After Reverse: %s\n", strArray);
}

void swap(char* a, char* b){
    char c = *a;
    *a = *b;
    *b = c;
}

void reverse(char* str) {
    // handle the special case when it is an empty string
    if (!*str) {
        return;
    }

    // mark down the begin of the string
    char* begin = str;

    // pointing to the last character
    char* end = begin + strlen(str) - 1;

    // swap begin and end
    while (begin < end) {
        swap(begin, end);
        begin++;
        end--;
    }
}

差点忘掉还可以用 strlen() 这个函数来写 计算字符串长度的。。。。哎， 我是多久没有写代码了。。