Submission #850026

#	Time	Username	Problem	Language	Result	Execution time	Memory
850026		Mr_Ph	Monochrome Points (JOI20_monochrome)	C++14	0 / 100	1 ms	456 KiB

monochrome

///Never gonna give you up.
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
typedef long long ll;
typedef long long int lli;
typedef unsigned long long ull;
using namespace std;
using namespace __gnu_pbds;
template<class x>
using ordered_set = tree<x, null_type,less<x>, rb_tree_tag,tree_order_statistics_node_update>;
const ll mod=(ll)1e9+7;
const ll mod1=998244353;
///the defines :)
//#define endl '\n'
#define vi vector<int>
#define vll vector<ll>
#define ent(arr) for(int i=0;i<arr.size();i++)cin>>arr[i];
#define all(arr) arr.begin(),arr.end()
#define allr(arr) arr.rbegin(),arr.rend()
#define sz size()
#define int long long
void preprocess() {}
void solve()
{
    int n;
    cin>>n;
    string s;
    cin>>s;
    map<int,char>mp;
    vi arr;
        vi arr1;
    int xd=0;
    for(int i=0;i<s.sz;i++)
    {
        if(s[i]=='W')arr.push_back(i+1);
        else arr1.push_back(i+1);
    }
    do
    {
        bool valid=false;
        for(int i=0;i<arr.sz-1;i++)
        {
            if(s[arr[i]-1]==s[arr1[i+1]-1])
                {
                    valid=true;
                    break;
                }
        }
        if(valid)continue;
        map<pair<int,int>,int>mp;
        for(int i=0;i<arr.sz-1;i++)
            mp[{arr[i],arr1[i+1]}]++;
        int ans=0;
        for(int i=0;i<arr.sz-1;i++)
        {
            int lol=0;
            map<pair<int,int>,int>mp1;
            int l=arr[i],r=arr1[i+1];
            while(!mp1[{l,r}]&&!mp1[{r,l}])
            {
                l--,r++;
                if(l<1)l=n;
                if(r>n)r=1;
                mp1[{l,r}]++;
                mp1[{r,l}]++;
                lol+=mp[{l,r}]|mp[{r,l}];
            }
            map<pair<int,int>,int>mp2;
            l=arr[i],r=arr1[i+1];
            while(!mp2[{l,r}]&&!mp2[{r,l}])
            {
                l++,r--;
                if(r<1)r=n;
                if(l>n)l=1;
                mp2[{l,r}]++;
                mp2[{r,l}]++;
                lol+=mp[{l,r}]|mp[{r,l}];
            }
          //  cout<<lol<<endl;
            ans+=((n-1)-lol);
        }
        xd=max(xd,ans);
       // cout<<"-----------"<<endl;
    }while(next_permutation(all(arr)));
    cout<<xd/2<<endl;
}
signed main()
{
    // freopen("div7.in","r",stdin);
    //freopen("div7.out","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    preprocess();
    //bla();
    int t=1;
    //cin>>t;
    while(t--)
        solve();
}

Compilation message (stderr)

monochrome.cpp: In function 'void solve()':
monochrome.cpp:34:18: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |     for(int i=0;i<s.sz;i++)
      |                  ^
monochrome.cpp:42:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for(int i=0;i<arr.sz-1;i++)
      |                     ~^~~~~~~~~
monochrome.cpp:52:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |         for(int i=0;i<arr.sz-1;i++)
      |                     ~^~~~~~~~~
monochrome.cpp:55:22: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |         for(int i=0;i<arr.sz-1;i++)
      |                     ~^~~~~~~~~

• Subtask 1: 0 / 4
• Subtask 2: 0 / 21
• Subtask 3: 0 / 10
• Subtask 4: 0 / 65