Submission #239482

#	Time	Username	Problem	Language	Result	Execution time	Memory
239482		m3r8	Aliens (IOI16_aliens)	C++14	4 / 100	8 ms	5120 KiB

aliens

#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <vector>
#include <utility>
#include "aliens.h"


#define N 100100
#define M 1001000
#define ll long long
#define ii std::pair<int,int>

ll over[N];
int line[M];
std::vector<ii> pt;

ll minl(ll a, ll b){
  if(a == -1)return b;  
  if(b == -1)return a;
  return a < b ? a:b;
};
ll take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c){
  memset(over,0,sizeof(over));
  memset(line,0,sizeof(line));
  std::vector<std::vector<ll>> dp(n+10,std::vector<ll>(k+10,-1));
  pt.clear();

  for(int i = 0;i<n;i++){
    if(r[i] >= c[i]){
      line[c[i]] = std::max(line[c[i]],r[i]-c[i]+1);
    }else if(r[i] < c[i]){
      line[r[i]] = std::max(line[r[i]],c[i]-r[i]+1);  
    };
  };

  for(int i = 0;i<m;i++){
    if(line[i])pt.push_back(ii(i,line[i]));  
  };

  for(int i = 1;i<pt.size();i++){
    if(over[i-1] > pt[i-1].second){
      over[i] = over[i-1] + pt[i-1].first - pt[i].first;  
    }else{
      over[i] = pt[i-1].second + pt[i-1].first - pt[i].first;
    };
    if(over[i] < 0)over[i] = 0;
    //printf("pt: %d %d %d\n",pt[i].first,pt[i].second,over[i]);
  };

  //printf("%d %d %d %d\n",pt.size(),pt[0].first,pt[0].second,over[0]);
  for(int i = 0;i<=k;i++)dp[0][i] = 0;
  int iprev = 0;
  ll mx = 0;
  ll inlf,t1,t2;
  for(int j = 1;j<=k;j++){
    mx = 0;
    for(int i = 1;i<=pt.size();i++){
      mx = std::max(mx, (ll)pt[i-1].second + pt[i-1].first - pt[iprev].first);
      inlf = std::max(0ll,mx * mx - over[iprev]*over[iprev]);
      t1 = dp[iprev][j-1] + inlf;
      inlf = std::max(0ll, pt[i-1].second * pt[i-1].second - over[i-1] * over[i-1]);
      t2 = dp[i-1][j-1] + inlf; 
      if(t1 < t2 || dp[i-1][j-1] == -1){
        dp[i][j] = t1; 
      }else{
        dp[i][j] = t2;  
        iprev = i-1;
        mx = pt[i-1].second;
      };
    };  
  };
  ll mn = -1;
  for(int i = 0;i<=k;i++){
    //printf("%lld\n",dp[pt.size()][i]);
    mn = minl(mn,dp[pt.size()][i]);  
  };
  return mn;
};

Compilation message (stderr)

aliens.cpp: In function 'long long int take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:41:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 1;i<pt.size();i++){
                 ~^~~~~~~~~~
aliens.cpp:58:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for(int i = 1;i<=pt.size();i++){
                   ~^~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 0 / 12
• Subtask 3: 0 / 9
• Subtask 4: 0 / 16
• Subtask 5: 0 / 19
• Subtask 6: 0 / 40