手写hash（int对int）
<pre><code class="language-cpp">#include <iostream>
#include <cstring>
#include <algorithm>
using namespace std;
namespace Hash{
struct Line{int u, v, next;}e[1000000];
const int HashMod=100007;
int h[HashMod], cnt;
inline int Add(int u, int v, int w){e[++cnt] = (Line){w, v, h[u]}; h[u] = cnt;return v;}
inline void clear(){memset(h, 0, sizeof(h)); cnt = 0;}
inline void insert(int x, int k = 0){//插入新的映射对
int s = x % HashMod;
Add(s, k, x);
}
void updata(int x, int k = 0){//修改映射值
int s = x % HashMod;
for(int i = h[s]; i; i = e[i].next)
if(e[i].u == x){
e[i].v = k;
return;
}
Add(s, k, x);
}
inline int query(int x){//查询映射值
int s = x % HashMod;
for(int i = h[s]; i; i = e[i].next)
if(e[i].u == x) return e[i].v;
return 0;
}
inline int count(int x){//判断是否存在映射的键值
int s = x % HashMod;
for(int i = h[s]; i; i = e[i].next)
if(e[i].u == x) return 1;
return 0;
}
inline int add(int x)//映射值自加1
{
int s = x % HashMod;
for(int i = h[s]; i; i = e[i].next)
if(e[i].u == x) return e[i].v = e[i].v + 1;
return Add(s, 1, x);
}
inline int sub(int x)//映射值自减1
{
int s = x % HashMod;
for(int i = h[s]; i; i = e[i].next)
if(e[i].u == x) return e[i].v = e[i].v - 1;
return Add(s, -1, x);
}
}</code></pre>