#include "aliens.h"
#include <bits/stdc++.h>
#define fi first
#define se second
using namespace std;
typedef long double ld;
typedef long long ll;
typedef pair<ll,ll> pl;
vector<pl> pii, ar;
pl lines[100010]; int Sv[100010];
int fr, bk;
ll Dp[100010]; int Cn[100010];
ld cr(pl a, pl b) { return (ld)(a.se-b.se)/(b.fi-a.fi); }
void insert(ll p, ll q)
{
lines[bk]={p,q};
while (bk>1 && cr(lines[bk-1], lines[bk-2])>cr(lines[bk-1], lines[bk])) {
lines[bk-1]=lines[bk]; bk--;
}
bk++;
}
ll f(ll x) {
while (fr+1<bk&&cr(lines[fr], lines[fr+1])<=(ld)x) fr++;
return x*x+lines[fr].fi*x+lines[fr].se;
}
ll take_photos(int n, int m, int k, vector<int> r, vector<int> c) {
int i, j;
for (i=0; i<n; i++) if (r[i]<c[i]) swap(r[i], c[i]);
for (i=0; i<n; i++) pii.push_back({(ll)r[i],(ll)c[i]});
sort(pii.begin(), pii.end());
for (i=0; i<n; i++) {
while (ar.size()&&ar.back().se>=pii[i].se) ar.pop_back();
ar.push_back(pii[i]);
}
ll st=-1, re=(ll)m*m;
ll ans=(ll)m*m;
while (st+1<re)
{
fr=bk=0;
for (i=0; i<ar.size(); i++) Sv[i]=Cn[i]=0;
insert(-2*(ar[0].se-1), (ar[0].se-1)*(ar[0].se-1));
ll md=(st+re)/2;
for (i=0; i<ar.size(); i++) {
Dp[i]=f(ar[i].fi)+md;
Cn[i]=Cn[Sv[fr]]+1;
if (i==n-1) continue;
if (ar[i].fi<ar[i+1].se) insert(-2*(ar[i+1].se-1), Dp[i]+(ar[i+1].se-1)*(ar[i+1].se-1));
else insert(-2*(ar[i+1].se-1), Dp[i]+(ar[i+1].se-1)*(ar[i+1].se-1)-(ar[i].fi-ar[i+1].se+1)*(ar[i].fi-ar[i+1].se+1));
Sv[bk-1]=i;
}
if (Cn[ar.size()-1]<=k) re=md;
else st=md;
if (Cn[ar.size()-1]<=k) ans=min(ans, Dp[ar.size()-1]-Cn[ar.size()-1]*md);
}
return ans
}
Compilation message
aliens.cpp: In function 'll take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:45:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (i=0; i<ar.size(); i++) Sv[i]=Cn[i]=0;
~^~~~~~~~~~
aliens.cpp:48:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for (i=0; i<ar.size(); i++) {
~^~~~~~~~~~
aliens.cpp:61:1: error: expected ';' before '}' token
}
^
aliens.cpp:32:9: warning: unused variable 'j' [-Wunused-variable]
int i, j;
^