## 답안 #166601

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
166601 2019-12-03T02:30:59 Z thiago4532 Building Bridges (CEOI17_building) C++17
0 / 100
132 ms 3488 KB
#include <bits/stdc++.h>
#define int int64_t
using namespace std;
const int maxn = 1e5 + 10;
int h[maxn], pref[maxn], w[maxn];
int n, dp[maxn];

struct line {
int a, b;

line(int a, int b): a(a), b(b) {

}

bool operator<(line const& l) const {
return a < l.a;
}
};

template<typename Arg>
bool bad(Arg&& l1, Arg&& l2, Arg&& l3) {
return (l2.a - l1.a)*(l3.b - l1.b) <= (l3.a -  l1.a)*(l2.b - l1.b);
}

set<line> lines;

lines.insert(l);

while(lines.size() > 2) {
auto it1 = lines.find(l);
if(it1 == lines.begin()) break;
it1--;
if(it1 == lines.begin()) break;
auto it2 = it1;
it1--;
if(it1 == lines.begin()) break;
auto it3 = it1;
it1--;

if ( bad(*it3, *it2, *it1) )
lines.erase(it2);
else
break;
}

while(lines.size() > 2) {
auto it1 = lines.find(l);
it1++;
if(it1 == lines.end()) break;
auto it2 = it1;
it1++;
if(it1 == lines.end()) break;
auto it3 = it1;
it1++;
if(it1 == lines.end()) break;

if ( bad(*it3, *it2, *it1) )
lines.erase(it2);
else
break;
}
}

inline int f(line const& l, int x) {
return l.a*x + l.b;
}

int query(int x) {
int res=0x3f3f3f3f3f3f3f3f;
for(auto& e : lines) {
// cout << f(e, x) << " ";
res = min(res, f(e,x));
}
// cout << "\n";
return res;
}

int32_t main() {
cin >> n;
for(int i=1;i<=n;i++)
cin >> h[i];

for(int i=1;i<=n;i++)
cin >> w[i], pref[i] = pref[i-1] + w[i];

dp[1] = 0;
add({-2*h[1], h[1]*h[1] + dp[1] - pref[1]});

for(int i=2;i<=n;i++) {
// dp[i] = 0x3f3f3f3f3f3f3f3f;

// for(int j=1;j<i;j++) {
// 	dp[i] = min(dp[i], dp[j] - pref[j] + h[j]*h[j] - 2*h[j] * h[i]);
// }

dp[i] = query(h[i]);

dp[i] += h[i]*h[i] + pref[i-1];
add({-2*h[i], h[i]*h[i] + dp[i] - pref[i]});
}
cout << dp[n] << "\n";
return 0;
}

#### Subtask #1 0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 380 KB Output is correct
2 Incorrect 2 ms 376 KB Output isn't correct
3 Halted 0 ms 0 KB -

#### Subtask #2 0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Incorrect 132 ms 3488 KB Output isn't correct
2 Halted 0 ms 0 KB -

#### Subtask #3 0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 380 KB Output is correct
2 Incorrect 2 ms 376 KB Output isn't correct
3 Halted 0 ms 0 KB -