短文评估[Hash]

Hash表

Hash最好用map+unsigned long long 写,不用取模,自动溢出

#define ULL unsigned long long 
map<ULL,int> Map;

while(pd(ch=getchar())){
    if(ch>='A'&&ch<='Z') ch=ch+'a'-'A';
    sum=sum*31+ch;
}
Map[sum]++;

for(map<ULL,int>::iterator i=Map.begin();i!=Map.end();i++)
    int cur=i->second;

代码 

#include<bits/stdc++.h>
#define ULL unsigned long long 
using namespace std;
map<ULL,int> Map;
bool pd(char ch){
    if((ch>='a'&&ch<='z')||(ch>='A'&&ch<='Z')) return true;
    return false;
}
bool read(){
    char ch; ULL sum=0;
    while(!pd(ch=getchar())) if(ch==EOF) return 0;
    
    if(ch>='A'&&ch<='Z') ch=ch+'a'-'A';
    sum=sum*31+ch;
    
    while(pd(ch=getchar())){
    if(ch>='A'&&ch<='Z') ch=ch+'a'-'A';
    sum=sum*31+ch;
    }
    Map[sum]++;
    return 1;
}
int main()
{
    int n,ans=0,cnt=0;
    while(read()) cnt++;
    for(map<ULL,int>::iterator i=Map.begin();i!=Map.end();i++){
    int cur=i->second;
    ans+=cur*cur*cur*cur;
    }
    cout<<ans<<" "<<cnt;
    return 0;
}