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답안 #1108559

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1108559 2024-11-04T12:47:20 Z wayzzjr Building Bridges (CEOI17_building) C++17
100 / 100
 53 ms 67408 KB 
// ----------------------- TEMPLATE NO.4 ---------------------------
#include<bits/stdc++.h>
using namespace std;

#define ll long long
const int N = 1e5 + 100;
const int MX = 1e6 + 2;
const ll oo = 1e16;

// loops
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define ROF(i, b, a) for (int i = (b), _a = (a); i >= _a; --i)

// others :>
#define nl '\n'
//----------------------------------SOLUTION-----------------------------------//

int n;
ll w[N], h[N], dp[N], pre[N];

struct line{
	ll a, b;
	line() : a(0), b(oo) {}
	line(ll a, ll b) : a(a), b(b) {}

	ll calc(ll x) { return a * x + b; }

	ll slope() { return a; }
} f[4 * MX];

#define mid ((lx + rx) / 2)
void update(int idx, int lx, int rx, line x){
	if(lx == rx){
		f[idx] = (x.calc(lx) < f[idx].calc(lx) ? x : f[idx]);
		return;
	}

	if(f[idx].calc(mid) > x.calc(mid)) swap(x, f[idx]);

	if(f[idx].slope() < x.slope())
		update(idx<<1, lx, mid, x);
	if(f[idx].slope() > x.slope())
		update(idx<<1|1, mid+1, rx, x);
}

ll query(int idx, int lx, int rx, int p){
	ll cur = f[idx].calc(p);
	if(lx == rx) return cur;
	if(p <= mid)
		return min(cur, query(idx<<1, lx, mid, p));
	else
		return min(cur, query(idx<<1|1, mid+1, rx, p));
}

ll sqr(ll x){
	return x * x;
}

void solve(){
	cin >> n;
	FOR(i, 1, n) cin >> h[i];
	FOR(i, 1, n) cin >> w[i];
	FOR(i, 1, n) pre[i] = pre[i-1] + w[i];

	// dp[i] = min(dp[j] + h[i] ^ 2 - 2 * h[i] * h[j] + h[j] ^ 2 + pre[i-1] - pre[j])
	// dp[i] = min(dp[j] + h[j] ^ 2 - pre[j]  -  2 * h[i] * h[j]) + h[i] ^ 2 + pre[i-1]
	update(1, 0, MX, line(-2 * h[1], sqr(h[1]) - pre[1]) );
	FOR(i, 2, n){
		dp[i] = query(1, 0, MX, h[i]) + sqr(h[i]) + pre[i-1];
		update(1, 0, MX, line(-2 * h[i], dp[i] + sqr(h[i]) - pre[i]));
	}
	cout << dp[n];
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	#define Wayzz "name"
	if (fopen (Wayzz".inp", "r")) {
		freopen (Wayzz".inp", "r", stdin);
		freopen (Wayzz".out", "w", stdout);
	}
	int T = 1;
    while(T--) solve();
	cerr <<"\nTime Elapse: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
}

Compilation message

building.cpp: In function 'int main()':
building.cpp:79:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |   freopen (Wayzz".inp", "r", stdin);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
building.cpp:80:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   80 |   freopen (Wayzz".out", "w", stdout);
      |   ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 64080 KB Output is correct
2 Correct 9 ms 64080 KB Output is correct
3 Correct 9 ms 64092 KB Output is correct
4 Correct 9 ms 64248 KB Output is correct
5 Correct 9 ms 64080 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 46 ms 66120 KB Output is correct
2 Correct 41 ms 66120 KB Output is correct
3 Correct 43 ms 66216 KB Output is correct
4 Correct 43 ms 66028 KB Output is correct
5 Correct 38 ms 66128 KB Output is correct

Subtask #3
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 9 ms 64080 KB Output is correct
2 Correct 9 ms 64080 KB Output is correct
3 Correct 9 ms 64092 KB Output is correct
4 Correct 9 ms 64248 KB Output is correct
5 Correct 9 ms 64080 KB Output is correct
6 Correct 46 ms 66120 KB Output is correct
7 Correct 41 ms 66120 KB Output is correct
8 Correct 43 ms 66216 KB Output is correct
9 Correct 43 ms 66028 KB Output is correct
10 Correct 38 ms 66128 KB Output is correct
11 Correct 49 ms 67408 KB Output is correct
12 Correct 51 ms 67072 KB Output is correct
13 Correct 45 ms 67184 KB Output is correct
14 Correct 53 ms 67144 KB Output is correct
15 Correct 38 ms 66868 KB Output is correct
16 Correct 38 ms 66888 KB Output is correct
17 Correct 27 ms 67152 KB Output is correct
18 Correct 26 ms 67164 KB Output is correct