qsort
int comp(const void *a,const void *b)
{
struct node*c=(node*)a;
struct node*d=(node*)b;
if(c->x!=d->x)
return c->x-d->x;
else
return c->y-d->y;
}
qsort(s,m,sizeof(s[0]),comp);
qsort的二级排序完整代码：
#include<stdio.h>
#include<stdlib.h>
#define MAX 1000
#define swap(a,b) {t=a;a=b;b=t;}//编译预处理命令中的宏定义
int t;
struct node
{
int x;
int y;
}s[100];
int comp(const void *a,const void *b)
{
struct node*c=(node*)a;
struct node*d=(node*)b;
if(c->x!=d->x)
return c->x-d->x;
else
return c->y-d->y;
}
int main()
{
int n;
scanf("%d",&n);
while(n--)
{
int i,m;
scanf("%d",&m);
for(i=0;i<m;i++)
{
scanf("%d%d",&s[i].x,&s[i].y);
}
qsort(s,m,sizeof(s[0]),comp);
/*for(i=0;i<m;i++)//排序，可重复
{
printf("%d %d\n",s[i].x,s[i].y);
}*/
for(i=0;i<m-1;i++)//去掉重复的
{
if(s[i].x==s[i+1].x &&s[i].y==s[i+1].y)
continue;
printf("%d %d\n",s[i].x,s[i].y);
}
printf("%d %d\n",s[m-1].x,s[m-1].y);
}
return 0;
}
