C语言合并字符串

阳光穿透心脏的1/2处 2022-03-07 07:38 346阅读 0赞

**注意：**  
注意字符串结束条件的判断。

/*---------------------------
    功能：合并字符串
    描述：将str2逆序插入到str1中
    输入示例：
    ABCDEFGHIJK
    1234
    输出示例：
    A4B3C2D1EFGHIJK
    ----------------------------
    Author: Zhang Kaizhou
    Date: 2019-3-16 14:47:41
    ---------------------------*/
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #define MAXSIZE 1000
    
    void combine_str(char * str1, char * str2, char * str);
    
    int main(){
        char * str1, * str2, * str;
        str1 = (char *)calloc(MAXSIZE, sizeof(char));
        str2 = (char *)calloc(MAXSIZE, sizeof(char));
        str = (char *)calloc(MAXSIZE, sizeof(char));
        gets(str1);
        gets(str2);
        combine_str(str1, str2, str);
        puts(str);
    
        return 0;
    }
    
    void combine_str(char * str1, char * str2, char * str){
        int len, i;
        char * temp = (char *)calloc(MAXSIZE, sizeof(char));
        len = strlen(str1) + strlen(str2);
        for(i = 0; i < strlen(str2); i++){
            temp[i] = str2[strlen(str2) - 1 - i];
        }
        temp[i] = '\0';
        for(i = 0; i < len; i++){
            if(i % 2 == 0){ // 偶数位
                if(* str1 != '\0'){
                    str[i] = * str1;
                    str1++;
                    continue;
                }else if(* temp != '\0'){
                    str[i] = * temp;
                    temp++;
                    continue;
                }
            }else{ // 奇数位
                if(* temp != '\0'){
                    str[i] = * temp;
                    temp++;
                    continue;
                }else if(* str1 != '\0'){
                    str[i] = * str1;
                    str1++;
                    continue;
                }
            }
        }
        return;
    }