Alice bought a lot of pairs of socks yesterday. But when she went home, she found that she has lost one of them. Each sock has a name which contains exactly 7 charaters.
Alice wants to know which sock she has lost. Maybe you can help her.
Input
There are multiple cases. The first line containing an integer n (1 <= n <= 1000000) indicates that Alice bought n pairs of socks. For the following 2*n-1 lines, each line is a string with 7 charaters indicating the name of the socks that Alice took back.
Output
The name of the lost sock.
Sample Input
2 aabcdef bzyxwvu bzyxwvu 4 aqwerty eas fgh aqwerty easdfgh easdfgh aqwerty aqwerty 2 0x0abcd 0ABCDEF 0x0abcd
Sample Output
aabcdef eas fgh 0ABCDEF
Hint
Because of HUGE input, scanf is recommended.
方法1：
#include<cstdio>
#include<cmath>
#include<cstring>
#include<stdlib.h>
char a[2000005][8];
//注;若用qsort对二维数组排序 应该用strcmp 若不是-
int cmp(const void *a,const void *b)
{
return strcmp((char*)a,(char*)b);
}
int main()
{
int i,j,k;
int n;
//快排，检测相邻的字符串
while(scanf("%d",&n)!=-1)
{
getchar();
for(i=0;i<2*n-1;i++)
gets(a[i]);
qsort(a,2*n-1,sizeof(a[0]),cmp);
if(strcmp(a[0],a[1])!=0) {printf("%s
",a[0]);continue;}
for(i=0;i<2*n-1;i+=2)
if(strcmp(a[i],a[i+1])!=0) {printf("%s
",a[i]);break;}
}
}
方法2：每一串都为7个字符，用数组对每一串的每一个字符计数 若最后某字符的个数为奇数 输出该字符（get）