潘瑞

```c

#include
#include
#include
#define M 20
typedef struct{
int xuehao;
char xingming[M];
char zhuanye[M];
int banhao;
}xinxi;
typedef struct{
xinxi student[M-1];
int len;
}students;
students *creat(int n)
{
int i;
students *s;
s = (students *)malloc(sizeof(students));
s->len=0;
printf("姓名\t学号\t专业\t班号：\n");
for (i=1; i<=n; i++)
{
scanf("%s%d%s%d", &s->student[i].xingming,&s->student[i].xuehao,&s->student[i].zhuanye,&s->student[i].banhao);
s->len++;
}
return s;
}
//排序
students* quicksort(students *tab,int left,int right)
{
int i,j;
if(leftstudent[0]=tab->student[i];
do
{
while(tab->student[j].xuehao>tab->student[0].xuehao&&istudent[i]=tab->student[j];
i++;
}
while(tab->student[i].xuehaostudent[0].xuehao&&istudent[j]=tab->student[i];
j--;
}
}while(i!=j);
tab->student[i]=tab->student[0];
quicksort(tab,left,i-1);
quicksort(tab,i+1,right);
}
return tab;
}
//顺序检索
void seqsever(students *s,char zhuanye[M])
{
int k;
printf("顺序检索结果为：\n");
for(k=1;k<=s->len;k++)
{
if(strcmp(s->student[k].zhuanye,zhuanye)==0)
printf("%s\t%d\t%s\t%d\n",s->student[k].xingming,s->student[k].xuehao,s->student[k].zhuanye,s->student[k].banhao);
}
}
//二分法检索非递归
int binsearch1(students *s,int key)
{
int low=1,high=s->len,mid;
while(low<=high)
{
mid=(low+high)/2;
if(s->student[mid].xuehao==key)
{
printf("二分法检索结果为：\n");
printf("%s\t%d\t%s\t%d\n",s->student[mid].xingming,s->student[mid].xuehao,s->student[mid].zhuanye,s->student[mid].banhao);
}
if(s->student[mid].xuehao>key)
high=mid-1;
else
low=mid+1;
}
return -1;
}

int main()
{
students *p;
int key,i,n;
char zhuanye[M];
p = (students *)malloc(sizeof(students));
printf("请输入你需要输入的信息的个数：");
scanf("%d", &n);
getchar();
p=creat(n);
//快速排序
p=quicksort(p,0,p->len);
printf("\n按学号排序输出结果为：\n");
for (i=1; i<=p->len; i++)
printf("%s\t%d\t%s\t%d\n",p->student[i].xingming,p->student[i].xuehao,p->student[i].zhuanye,p->student[i].banhao);
//顺序检索
getchar();
printf("\n请输入需要查找的专业：");
scanf("%s",&zhuanye);
//gets(zhuanye);
seqsever(p,zhuanye);
//二分法检索
printf("\n请输入需要查找的学号：");
scanf("%d",&key);
binsearch1(p,key);
return 0;
}
```