Submission #1061356

#	Time	Username	Problem	Language	Result	Execution time	Memory
1061356		vjudge1	Mountains (IOI17_mountains)	C++17	40 / 100	524 ms	8600 KiB

mountains

#include "mountains.h"
using namespace std;
int C[2010][2010];
vector<int>adj[2010];
int DDDP[1<<20];
int maximum_deevs(vector<int> y) {
    int n=y.size();
    for(int i=1;i<n;i++){
        int uuu=i-1;
        C[i][i-1]=C[i-1][i]=1;
        for(int j=i-1;j--;) {
            long long ht=y[j]-y[i],dt=i-j;
            long long hb=y[uuu]-y[i],db=i-uuu;
            if(ht*db>=hb*dt)
                C[i][j]=C[j][i]=1,uuu=j;
        }
    }
    int ans=0;
    int sz1=n/2,sz2=n-sz1;
    for(int i=0;i<1<<sz2;i++){
        vector<int>v;
        for(int j=0;j<sz2;j++) if(i&1<<j)
            v.push_back(sz1+j),DDDP[i]=max(DDDP[i],DDDP[i^1<<j]);
        int bad=0;
        for(auto A:v)
            for(auto B:v)
                if(C[A][B])
                    bad=1;
        if(!bad)DDDP[i]=v.size();
    }
    for(int i=0;i<1<<sz1;i++){
        int K2=1<<sz2;
        int todo=0,bad=0;
        K2--;
        vector<int>v;
        for(int j=0;j<sz1;j++)
            if(i&1<<j)
                v.push_back(j);
        for(auto A:v)
            for(auto B:v)
                if(C[A][B])
                    bad=1;
        if(!bad){
            for(auto A:v)
                for(int i=sz1;i<n;i++)
                    if(C[A][i])
                        todo|=1<<i-sz1;
            ans=max(ans,DDDP[K2^todo]+(int)v.size());
        }
    }
    return ans;
}

Compilation message (stderr)

mountains.cpp: In function 'int maximum_deevs(std::vector<int>)':
mountains.cpp:47:35: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   47 |                         todo|=1<<i-sz1;
      |                                  ~^~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 30
• Subtask 4: 0 / 30