［c语言］EmailAddresses（for hw）

You’ve gathered some e-mail addresses from a variety of sources, and you want to send out a mass mailing to all of the addresses. However, you don’t want to send out duplicate messages. You need to write a program that reads all e-mail addresses and discards any that already have been input.

Input

The first line is a positive integer for the number of e-mail addresses which is smaller than 50. Then each of the e-mail addresses is input in one line.

Output

Output the new mailing list in lexicographic order. Each e-mail address in one line.

Note: ignore letter case when comparing two e-mail addresses, but the output is case sensitive.

Sample Input

10

toocle01@netsun.com

chuangling@chuangling.net

zjykrc@163.com

hahdjx@163.com

5663@sohu.com

toocle01@netsun.com

chenql_008@163.com

tsmoql@alibaba.com.cn

LYC@hzlasiji.com

zjykrc@163.com

Sample Output

5663@sohu.com

chenql_008@163.com

chuangling@chuangling.net

hahdjx@163.com

LYC@hzlasiji.com

toocle01@netsun.com

tsmoql@alibaba.com.cn

zjykrc@163.com

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
//在快排的比较函数中，把字符串存放在另一个指针中，把这个指针中的字符转化为小写再排序。不能改变原来指针的内容！
//尽量使用strncpy， 同时最后一个参数要用strlen（）＋ 1，表示加上字符串最后一个／0；
int comp(const void*a, const void*b) {
char p1[200];
char p2[200];
strncpy(p1, (char*)a, strlen((char*)a) + 1);
strncpy(p2, (char*)b, strlen((char*)b) + 1);
long length_1 = strlen(p1);
long length_2 = strlen(p2);
for (int i = 0; i < length_1; i++) {
p1[i] = tolower(p1[i]);
}
for (int i = 0; i < length_2; i++) {
p2[i] = tolower(p2[i]);
}
return strcmp((char*)p1,(char*)p2);
}

int main() {
int n;
scanf("%d", &n);
char address[100][100];
int i = 0;
while (n--) {
scanf("%s", address[i]);
i++;
}
qsort(address, i, sizeof(address[0]), comp);
int m;
for (m = 0; m < i - 1; m++) {
if (strcmp(address[m], address[m + 1]) == 0) {
strncpy(address[m], "0", strlen(address[m]) + 1);
}
}
for (m = 0; m < i; m++) {
if (strcmp(address[m], "0") != 0) {
printf("%s\n", address[m]);
}
}
return 0;
}