HashTable_Array.rar_哈希函数

#include<iostream> #include<string.h> #define N 20 using namespace std; struct Node//标记学生信息的结构体 { char name[20]; char num[10]; char address[20]; }; Node data[N]; int Hash(const char str[])//除留余数法的hash函数 { int i=0; int key=0; while(str[i]!=NULL) { key+=(int)str[i]; i++; } key=key%19; return key; } void Hashname(int usign[], int *K, char name[],char num[],char address[]) {//以名字为关键值输入哈希表 int key; int j; key=Hash(name); if(usign[key]==1) { for(j=1;j<N;j++)//以线性探测再散列的方式处理冲突 { key=(key+j)%N; if(usign[key]==0) break; } } usign[key]=1; strcpy(data[key].name,name); strcpy(data[key].num,num); strcpy(data[key].address,address); (*K)++; } int Searchname(const int KKK,const int usign[],const char uname[])//查找给定名字的数组下表 { int key; int j; int a=1; key=Hash(uname); if(usign[key]==0) { cout<<"无记录"<<endl; return(-1); } else if((usign[key]==1)&&strcmp(data[key].name,uname)!=0) { for(j=1;j<N,a<KKK;j++) { key=(key+j)%N;//线性探测再散列处理冲突 a++; if((usign[key]==1)&&strcmp(data[key].name,uname)==0) { return key; } } if(a>=KKK) return(-1); } else if((usign[key]==1)&&strcmp(data[key].name,uname)==0) return key; } void Outname(int uK,int usign[])//输出指定下表的元素 { if((uK<0)||(usign[uK]==0)) { cout<<"无记录"<<endl; return; } cout<<"姓名："<<data[uK].name<<endl; cout<<"学号："<<data[uK].num<<endl; cout<<"地址："<<data[uK].address<<endl; } void Outlist()//输出整个哈希表 { int i; for(i=0;i<N;i++) { cout<<"姓名："<<data[i].name<<endl; cout<<"学号："<<data[i].num<<endl; cout<<"地址："<<data[i].address<<endl; cout<<"******************************"<<endl; } } void main() { int sign[N]; int l; int n; for(l=0;l<N;l++) sign[l]=0; for(l=0; l<N; l++) { strcpy(data[l].address,""); strcpy(data[l].name,""); strcpy(data[l].num,""); } Node mdata; int knumber=0;//记录元素的个数 cout<<"\t\t____________________"<<endl; cout<<"\t\t*1 输入记录"<<endl; cout<<"\t\t*2 按姓名查找并显示记录"<<endl; cout<<"\t\t*3 显示全部记录"<<endl; cout<<"\t\t*4 退出"<<endl; cout<<"\t\t____________________"<<endl; while(1) { cout<<"请输入1-4："<<endl; cin>>n; switch(n) { case 1: int m; cout<<"请输入需要输入的记录条数：（不超过20）"<<endl; cin>>m; for(l=0;l<m;l++) { cout<<"请输入第"<<l+1<<"条记录："<<endl; cout<<"姓名："; cin>>mdata.name; cout<<"学号："; cin>>mdata.num; cout<<"地址："; cin>>mdata.address; Hashname(sign,&knumber,mdata.name,mdata.num,mdata.address); } break; case 2: char mname[10]; int mkey; cout<<"请输入姓名："<<endl; cin>>mname; mkey=Searchname(knumber,sign,mname); Outname(mkey,sign); break; case 3: Outlist(); break; case 4: exit(0); } } }