测试点输出

Wrong Answer.wrong answer Too short on line 1.

#include <cstdio>
#include <string.h>

int main() {
    int n; char str[12], tmpstr[12]; bool negative;
    scanf("%d", &n);
    if(n<0) {
        negative=true;
        n=-n;
    }
    sprintf(str, "%d", n);
    //printf("%s\n", str);
    int len = strlen(str); char tmp;
    for(int i = 0; i < len/2; i++) {
        tmp = str[i]; str[i] = str[len-i-1]; str[len-i-1] = tmp;
    }
    while(str[0]=='0') {
    	memset(tmpstr, 0, sizeof(char[12]));
    	strncpy(tmpstr, str+1, strlen(str)-1);
    	strcpy(str, tmpstr);
	}
    
    if(negative)printf("-");
    printf("%s\n", str);
    return 0;
}

字符串写法，其他点AC