Submission #1066621

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066621		vjudge1	Building Bridges (CEOI17_building)	C++17	100 / 100	42 ms	13140 KiB

building

    ///huynhocute123///
#include<bits/stdc++.h>
using namespace std;
#define S second
#define F first
#define pii pair<int,int>
#define piii pair<int,pair<int,int>>
#define pb push_back
#define pi M_PI
#define FOR(i, a, b) for(int i = a; i <= b; ++i)
#define REP(i, a, b) for(int i = b; i >= a; --i)
#define ALL(v) v.begin(),v.end()
#define ll long long
#define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
#define out(name) if(fopen(name, "w")) freopen(name, "w", stdout);
//random_device rd;
//mt19937 rng(rd());
#define int long long
const int maxN = 1e5 + 9 ;
const int  modd = 1e9 + 7;
const int base = 2309;
const int MAX = 1e9+9;
void minimize(int &u, int v){
    if(v < u) u = v;
}
void maximize(int &u, int v){
    if(v > u) u = v;
}
int n, k, t, m, res, a[maxN], f[maxN], b[maxN],dp[maxN];
int l, r;
bool vis[maxN];
vector<int> e[maxN];
struct Line {
	mutable ll k, m, p;
	bool operator<(const Line& o) const { return k < o.k; }
	bool operator<(ll x) const { return p < x; }
};

struct LineContainer : multiset<Line, less<>> {
	// (for doubles, use inf = 1/.0, div(a,b) = a/b)
	static const ll inf = LLONG_MAX;
	ll div(ll a, ll b) { // floored division
		return a / b - ((a ^ b) < 0 && a % b); }
	bool isect(iterator x, iterator y) {
		if (y == end()) return x->p = inf, 0;
		if (x->k == y->k) x->p = x->m > y->m ? inf : -inf;
		else x->p = div(y->m - x->m, x->k - y->k);
		return x->p >= y->p;
	}
	void add(ll k, ll m) {
		auto z = insert({k, m, 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, erase(y));
	}
	ll query(ll x) {
		assert(!empty());
		auto l = *lower_bound(x);
		return l.k * x + l.m;
	}
}line ;
void solve(){
    cin >> n;
    FOR(i ,1 , n)cin >> a[i];
    FOR(i, 1, n){
        cin >> b[i];
        f[i] = f[i-1] + b[i];
    }
    //  L[i] = { -2*a[i], dp[i] + a[i] * a[i]  - f[i]  };
    //   dp[i] = a[i] *S[id].a + S[id].b + a[i]*a[i] + f[i-1];
    /// dp[i] = QUERRY() + a[i]^ 2  + f[i-1]

    line.add(2 * a[1], - (a[1] * a[1] - f[1])  );
    FOR(i , 2, n){
        dp[i] = -line.query(a[i]) +a[i] * a[i] + f[i-1];
        line.add(2 * a[i] , f[i] - a[i] * a[i] - dp[i] );

    }
    cout << dp[n];

}
signed main(){
//    freopen("name.inp","r",stdin);
//    freopen("name.out","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    inp("task.inp");
    t = 1;
   // cin >> t;
    while( t-- )solve();

}

Compilation message (stderr)

building.cpp: In function 'int main()':
building.cpp:14:47: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 | #define inp(name) if(fopen(name, "r")) freopen(name, "r", stdin);
      |                                        ~~~~~~~^~~~~~~~~~~~~~~~~~
building.cpp:88:5: note: in expansion of macro 'inp'
   88 |     inp("task.inp");
      |     ^~~

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40