oj.uz

Submission #148116

# Submission time Handle Problem Language Result Execution time Memory
148116 2019-08-31T14:01:50 Z WhipppedCream Building Bridges (CEOI17_building) C++17
100 / 100
 84 ms 9848 KB 
#include <bits/stdc++.h>
#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")
using namespace std;
#define X first
#define Y second
#define pb push_back
typedef pair<int, int> ii;
typedef long long ll;

struct Line
{
	mutable ll m, b, p;
	bool operator < (const Line &o) const { return m< o.m; }
	bool operator < (ll o) const { return p< o; }
};

struct LineContainer : multiset<Line, less<>>
{
	const ll inf = LLONG_MAX;
	ll div(ll a, ll b)
	{
		return a/b - ((a^b)< 0 && a%b);
	}
	bool isect(iterator x, iterator y)
	{
		if(y == end()){ x->p = inf; return false; }
		if(x->m == y->m) x->p = x->b> y->b ? inf : -inf;
		else x->p = div(x->b - y->b, y->m - x->m);
		return x->p >= y->p;
	}
	void add(ll m, ll b)
	{
		auto z = insert({m, b, 0}), y = z++, x = y;
		while(isect(y, z)) z = erase(z);
		if(x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while((y = x)!= begin() && (--x)->p >= y->p) isect(x, y = erase(y));
	}
	ll query(ll x)
	{
		assert(!empty());
		auto l = *lower_bound(x);
		return l.m*x+l.b;
	}
};

LineContainer foo;

const int maxn = 1e5+5;
ll h[maxn];
ll qs[maxn];
ll dp[maxn];
int n;

int main()
{
	scanf("%d", &n);
	for(int i = 1; i<= n; i++) scanf("%lld", h+i);
	for(int i = 1; i<= n; i++)
	{
		scanf("%lld", qs+i);
		qs[i] += qs[i-1];
	} 
	dp[1] = 0;
	foo.add(2*h[1], -dp[1]+qs[1]-h[1]*h[1]);
	for(int i = 2; i<= n; i++)
	{
		dp[i] = qs[i-1]+h[i]*h[i]-foo.query(h[i]);
		foo.add(2*h[i], -dp[i]+qs[i]-h[i]*h[i]);
	}
	printf("%lld\n", dp[n]);
}

Compilation message

building.cpp: In function 'int main()':
building.cpp:57:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &n);
  ~~~~~^~~~~~~~~~
building.cpp:58:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(int i = 1; i<= n; i++) scanf("%lld", h+i);
                             ~~~~~^~~~~~~~~~~~~
building.cpp:61:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld", qs+i);
   ~~~~~^~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 3 ms 376 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 62 ms 3780 KB Output is correct
2 Correct 62 ms 3704 KB Output is correct
3 Correct 63 ms 3832 KB Output is correct
4 Correct 58 ms 3576 KB Output is correct
5 Correct 56 ms 4728 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 2 ms 376 KB Output is correct
4 Correct 2 ms 376 KB Output is correct
5 Correct 3 ms 376 KB Output is correct
6 Correct 62 ms 3780 KB Output is correct
7 Correct 62 ms 3704 KB Output is correct
8 Correct 63 ms 3832 KB Output is correct
9 Correct 58 ms 3576 KB Output is correct
10 Correct 56 ms 4728 KB Output is correct
11 Correct 63 ms 3832 KB Output is correct
12 Correct 65 ms 3820 KB Output is correct
13 Correct 52 ms 3704 KB Output is correct
14 Correct 64 ms 3980 KB Output is correct
15 Correct 84 ms 9848 KB Output is correct
16 Correct 56 ms 4728 KB Output is correct
17 Correct 33 ms 3704 KB Output is correct
18 Correct 33 ms 3704 KB Output is correct