拉链法
#include <iostream>
#include <cstring>
using namespace std;
const int N = 100003;//大于10的5次方的第一个质数,在hash中模上质数产生哈希冲突的概率小
int n;
int h[N], e[N], ne[N], idx;
void insert(int x){
int k = (x % N + N) % N;
e[idx] = x, ne[idx] = h[k], h[k] = idx++;
}
bool find(int x){
int k = (x % N + N) % N;
for(int i = h[k]; i != -1; i = ne[i]){
if(e[i] == x)
return true;
}
return false;
}
int main(){
cin >> n;
char op[10];
int x;
memset(h, -1, sizeof h);
while(n--){
scanf("%s%d", op, &x);
if(*op == 'I'){
insert(x);
}else{
if(find(x)) printf("Yes\n");
else printf("No\n");
}
}
return 0;
}
开放寻址法
···
include [HTML_REMOVED]
include [HTML_REMOVED]
using namespace std;
const int N = 200003/开放寻址法数组大小通常要开到数据范围的2倍/, null = 0x3f3f3f3f;
int h[N];
int find(int x){
int k = (x % N + N) % N;
while(h[k] != null && h[k] != x){
k++;
if(k == N) k = 0;
}
return k;
}
int main(){
int n;
cin >> n;
memset(h, 0x3f, sizeof h);
while(n –){
char op[2];
int x;
scanf(“%s%d”, op, &x);
int k = find(x);
if(*op == ‘I’){
h[k] = x;
}else{
if(h[k] != null) cout << “Yes” << endl;
else cout << “No” << endl;
}
}
return 0;
}
···