Submission #1076713

#	Time	Username	Problem	Language	Result	Execution time	Memory
1076713		RiverFlow	Fireworks (APIO16_fireworks)	C++14	26 / 100	14 ms	7768 KiB

fireworks

#include <bits/stdc++.h>

#define nl "\n"
#define no "NO"
#define yes "YES"
#define fi first
#define se second
#define vec vector
#define task "main"
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
#define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin())

using namespace std;

template<typename U, typename V> bool maxi(U &a, V b) {
    if (a < b) { a = b; return 1; } return 0;
}
template<typename U, typename V> bool mini(U &a, V b) {
    if (a > b) { a = b; return 1; } return 0;
}

const int N = (int)3e5 + 9;
const int mod = (int)1e9 + 7;

void prepare(); void main_code();

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    const bool MULTITEST = 0; prepare();
    int num_test = 1; if (MULTITEST) cin >> num_test;
    while (num_test--) { main_code(); }
}

void prepare() {};

vector<pair<int, int>> g[N];

long long h[N];

void fs(int u, int p) {
    for(auto v : g[u]) if (v.fi != p) {
        h[v.fi] = h[u] + v.se;
        fs(v.fi, u);
    }
}

int n, m;

namespace SUB2 {

const int N = 302;

int dp[N][N];

void dfs(int u, int p) {
    for(auto [v, w] : g[u]) {
        if (v > n) {
            FOR(vx, 0, 300) {
                dp[u][vx] += abs(w - vx);
            }
            continue ;
        }
        dfs(v, u);
        FOR(vx, 0, 300) {
            // ta dieu chinh cai w mot it
            int MIN = INT_MAX;
            FOR(nw, 0, vx) {
                MIN = min(MIN, dp[v][vx - nw] + abs(nw - w));
            }
            dp[u][vx] += MIN;
        }
    }
}

void sol() {
    dfs(1, 0);
    int ans = INT_MAX;
    FOR(v, 0, 300) {
        ans = min(ans, dp[1][v]);
    }
    cout << ans;
}
};

void main_code() {
    cin >> n >> m;
    for(int i = 2; i <= n + m; ++i) {
        int p, w; cin >> p >> w;
        g[p].push_back(_mp(i, w));
    }
    fs(1, 0);
    if (n == 1) {
        vector<int> val;
        FOR(i, 2, m + 1) val.push_back(h[i]);
        sort(all(val));
        int x = val[sz(val) / 2];
        long long ans = 0;
        for(int y : val) ans += abs(x - y);
        cout << ans;
        return ;
    }
    if (*max_element(h + 1, h + n + 1) <= 300) {
        return SUB2::sol(), void();
    };
}


/*     Let the river flows naturally     */

Compilation message (stderr)

fireworks.cpp: In function 'void SUB2::dfs(int, int)':
fireworks.cpp:66:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   66 |     for(auto [v, w] : g[u]) {
      |              ^
fireworks.cpp: In function 'int main()':
fireworks.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
fireworks.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 19 / 19
• Subtask 3: 0 / 29
• Subtask 4: 0 / 45