Submission #734572

#	Time	Username	Problem	Language	Result	Execution time	Memory
734572		abcvuitunggio	Mountains (IOI17_mountains)	C++17	0 / 100	9 ms	16004 KiB

mountains

#include "mountains.h"
#include <bits/stdc++.h>
using namespace std;
struct point{
    int x,y;
}p[2001];
inline point operator-(point a, point b){
    return {a.x-b.x,a.y-b.y};
}
inline int operator*(point a, point b){
    return a.x*b.y-a.y*b.x;
}
int dp[2001][2001];
vector <int> v[2001];
int f(int i, int j){
    if (i==j)
        return 1;
    if (i>j)
        return 0;
    if (dp[i][j]!=-1)
        return dp[i][j];
    int res=1;
    for (int k=0;k<v[j].size()-1;k++)
        res+=f(max(v[j][k]+1,i),v[j][k+1]-1);
    return dp[i][j]=max(f(i,j-1),res);
}
int maximum_deevs(vector <int> y){
    for (int i=1;i<=y.size();i++){
        v[i].push_back(0);
        p[i]={i,y[i-1]};
        for (int j=1;j<i;j++){
            while (v[i].size()>1&&(p[j]-p[i])*(p[v[i].back()]-p[i])>0)
                v[i].pop_back();
            v[i].push_back(j);
        }
    }
    memset(dp,-1,sizeof(dp));
    return f(1,y.size());
}

Compilation message (stderr)

mountains.cpp: In function 'int f(int, int)':
mountains.cpp:23:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   23 |     for (int k=0;k<v[j].size()-1;k++)
      |                  ~^~~~~~~~~~~~~~
mountains.cpp: In function 'int maximum_deevs(std::vector<int>)':
mountains.cpp:28:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |     for (int i=1;i<=y.size();i++){
      |                  ~^~~~~~~~~~

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