48 lines
1.1 KiB
C++
48 lines
1.1 KiB
C++
#include<iostream>
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#include<cstdio>
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#include<cstring>
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#include<map>
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#include<string>
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using namespace std;
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typedef long long ll;
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ll gcd(ll a,ll b){
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for(;a>0&&b>0;a>b?a%=b:b%=a);
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return a+b;
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}
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int main(){
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int T;
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while(scanf("%d",&T)!=EOF){
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while(T--){
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int n;
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scanf("%d",&n);
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map<string,int>m;
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ll ji=0,ou=0;
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m.clear();
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int i;
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for(i=1;i<=n;i++){
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string a;
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cin>>a;
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m[a]++;
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if(a.length()%2){
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ji++;
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}
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else ou++;
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}
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ll cnt=0;
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cnt=ji*ou;
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for(map<string,int>::iterator it=m.begin();it!=m.end();it++){
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if(it->second>1){
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cnt+=((it->second)*((it->second)-1)/2);
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}
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}
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ll sum=n*(n-1)/2;
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if(cnt==0)printf("0/1\n");
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else{
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ll g=gcd(cnt,sum);
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printf("%lld/%lld\n",cnt/g,sum/g);
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}
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}
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}
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return 0;
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}
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