Submission #477426

#	Time	Username	Problem	Language	Result	Execution time	Memory
477426		2548631	Building Bridges (CEOI17_building)	C++17	0 / 100	30 ms	62932 KiB

building

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pii> vii;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef vector<vii> vvii;

#define fastIO ios::sync_with_stdio(false), cin.tie(NULL)
#define forw(i, l, r) for( int i = (l) ; i < (r) ; i++ )
#define forb(i, r, l) for( int i = (r) ; i >= (l) ; i-- )
#define log2i(x) (64 - __builtin_clzll(1ll * (x)) - 1)
#define numBit(x) (__builtin_popcountll(1ll * (x)))
#define getBit(x, i) ((x) >> (i) & 1)
#define Pi acos(-1.0l)
#define sz(x) int(x.size())
#define mt make_tuple
#define mp make_pair
#define fi first
#define se second
#define pb push_back
#define pf push_front
#define pob pop_back
#define pof pop_front
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define debug(x) cerr << #x << " = " << x << '\n';

const int N = 1e5 + 7;
const ll inf = 1e18l;
int n;
ll h[N], w[N], dp[N];

struct Line {
    ll a, b;
    Line():a(0), b(inf) {}
    Line(ll _a, ll _b):a(_a), b(_b) {}
    ll operator ()(int x) {return a * x + b;}
}T[40 * N];

void upd(Line val, int idx, int l, int r) {
    if(l + 1 == r) {
        if(val(l) < T[idx](l)) T[idx] = val;
        return;
    }
    int k = idx << 1, mid = (l + r) >> 1;
    if(val.a < T[idx].a) swap(T[idx], val);
    if(val(mid) < T[idx](mid)) {
        swap(T[idx], val);
        upd(val, k + 1, mid, r);
    } else upd(val, k, l, mid);
}

ll get(int x, int idx, int l, int r) {
    if(l + 1 == r) return T[idx](x);
    int k = idx << 1, mid = (l + r) >> 1;
    if(x < mid) return min(get(x, k, l, mid), T[idx](x));
    else return min(T[idx](x), get(x, k + 1, mid, r));
}

int main() {
    fastIO;
#ifndef ONLINE_JUDGE
    freopen("test.inp", "r", stdin);
    freopen("test.out", "w", stdout);
#endif

    cin >> n;
    ll sum = 0;
    forw(i, 0, n) cin >> h[i];
    forw(i, 0, n) cin >> w[i], sum += w[i];

    dp[0] = -w[0];
    forw(i, 1, n) {
        upd(Line(-2 * h[i - 1], dp[i - 1] + h[i - 1] * h[i - 1]), 1, 0, 10 * N);
        dp[i] = get(h[i], 1, 0, 10 * N) + h[i] * h[i] - w[i];
    }
    cout << dp[n - 1] + sum;
    return 0;
}

Compilation message (stderr)

building.cpp: In function 'int main()':
building.cpp:71:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |     freopen("test.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
building.cpp:72:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   72 |     freopen("test.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40