Submission #125268

#	Time	Username	Problem	Language	Result	Execution time	Memory
125268		dragonslayerit	Mountains (IOI17_mountains)	C++14	100 / 100	133 ms	43816 KiB

mountains

#include "mountains.h"
#include <vector>
#include <algorithm>
#include <cstdio>
     
int memo[2001][2001];
int last[2001][2001];

int best[2001][2001];
int first[2001][2001];//if i is required

int solve(int begin,int end){
  if(begin==end) return 0;
  if(end-begin==1) return 1;
  if(memo[begin][end]!=-1) return memo[begin][end];
  int ans=solve(begin,last[begin][end-1])+solve(last[begin][end-1]+1,end);
  return memo[begin][end]=std::max(ans,solve(begin+1,end));
}
     
int maximum_deevs(std::vector<int> y) {
  for(int i=0;i<=y.size();i++){
    for(int j=0;j<=y.size();j++){
      memo[i][j]=-1;
    }
  }
  for(int i=0;i<y.size();i++){
    int k=i+1;
    for(int j=i+1;j<y.size();j++){
      if(1LL*(k-i)*(y[j]-y[i])>=1LL*(j-i)*(y[k]-y[i])){
    	k=j;
      }
      last[i][j]=k;
    }
  }
  for(int i=0;i<y.size();i++){
    best[i][i+1]=1;
  }
  for(int i=y.size()-1;i>=0;i--){
    for(int j=i+2;j<=y.size();j++){
      best[i][j]=std::max(best[i][last[i][j-1]]+best[last[i][j-1]+1][j],best[i+1][j]);
    }
  }
  
  return solve(0,y.size());
}

Compilation message (stderr)

mountains.cpp: In function 'int maximum_deevs(std::vector<int>)':
mountains.cpp:21:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<=y.size();i++){
               ~^~~~~~~~~~
mountains.cpp:22:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int j=0;j<=y.size();j++){
                 ~^~~~~~~~~~
mountains.cpp:26:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<y.size();i++){
               ~^~~~~~~~~
mountains.cpp:28:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int j=i+1;j<y.size();j++){
                   ~^~~~~~~~~
mountains.cpp:35:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i=0;i<y.size();i++){
               ~^~~~~~~~~
mountains.cpp:39:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int j=i+2;j<=y.size();j++){
                   ~^~~~~~~~~~

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