#include <stdio.h>
#include <stdlib.h>
 
//文字列の長さを求める関数
int myStrlen(char s[]){
    int i;
    for(i = 0; s[i] != '\0'; i++);
    return i;
}
 
//文字列を2回繰り返した文字列を作る関数
char *setDouble(char s[]){
    int i, size;
    char *tmp;
 
    //文字列の長さを求める
    size = myStrlen(s);
 
    //2倍の文字数＋終端文字1文字分のメモリを確保
    tmp = (char *)malloc(sizeof(char) * (2 * size + 1));
 
    //メモリ確保に失敗した場合
    if(tmp == NULL){
        printf("ERROR\n");
        return NULL;
    }
 
    //前半に元の文字列をコピー
    for(i = 0; i < size; i++){
        tmp[i] = s[i];
    }
 
    //後半にも元の文字列をコピー
    for(i = 0; i < size; i++){
        tmp[i + size] = s[i];
    }
 
    //文字列の終わり
    tmp[2 * size] = '\0';
 
    return tmp;
}
 
int main(){
    char s[100];
    char *p;
 
    //文字列を入力
    scanf("%s", s);
 
    //2回繰り返した文字列を作る
    p = setDouble(s);
 
    //表示
    printf("%s -> %s\n", s, p);
 
    //mallocで確保したメモリを解放
    free(p);
 
    return 0;
}
 

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