Submission #313833

#	Time	Username	Problem	Language	Result	Execution time	Memory
313833		spike1236	Construction of Highway (JOI18_construction)	C++14	16 / 100	2077 ms	3576 KiB

construction

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define sz size()
#define ll long long
#define ld long double
#define all(_v) _v.begin(), _v.end()
#define pii pair <int, int>
#define pll pair <ll, ll>
#define veci vector <int>
#define vecll vector <ll>


const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, -1, 1};
const double PI = 3.1415926535897932384626433832795;
const double eps = 1e-9;
const int MOD1 = 1e9 + 7;
const int MOD2 = 998244353;

ll _mergeSort(int arr[], int temp[], int left, int right);
ll mergee(int arr[], int temp[], int left, int mid, int right);

ll mergeSort(int arr[], int array_size) {
    int temp[array_size];
    return _mergeSort(arr, temp, 0, array_size - 1);
}

ll _mergeSort(int arr[], int temp[], int left, int right) {
    ll mid, inv_count = 0;
    if (right > left) {
        mid = (right + left) / 2;
        inv_count += _mergeSort(arr, temp, left, mid);
        inv_count += _mergeSort(arr, temp, mid + 1, right);
        inv_count += mergee(arr, temp, left, mid + 1, right);
    }
    return inv_count;
}

ll mergee(int arr[], int temp[], int left, int mid, int right) {
    int i, j, k;
    ll inv_count = 0;
    i = left;
    j = mid;
    k = left;
    while ((i <= mid - 1) && (j <= right)) {
        if (arr[i] <= arr[j]) {
            temp[k++] = arr[i++];
        }
        else {
            temp[k++] = arr[j++];
            inv_count = inv_count + (mid - i);
        }
    }
    while (i <= mid - 1)
        temp[k++] = arr[i++];
    while (j <= right)
        temp[k++] = arr[j++];
    for (i = left; i <= right; i++)
        arr[i] = temp[i];
    return inv_count;
}


const int MAXN = 1e5 + 10;
int n;
int c[MAXN];
int p[MAXN];

void solve() {
    cin >> n;
    for(int i = 1; i <= n; ++i)
        cin >> c[i];
    p[1] = -1;
    for(int i = 1; i < n; ++i) {
        int u, v;
        cin >> u >> v;
        p[v] = u;
        int x = u;
        veci inv_u;
        while(x != -1) inv_u.pb(c[x]), x = p[x];
        reverse(all(inv_u));
        int cntinv[inv_u.sz];
        ///cout << u << " : ";
        for(int j = 0; j < inv_u.sz; ++j) cntinv[j] = inv_u[j];
        ///for(auto it : inv_u) cout << it << ' ';
        ///cout << '\n';
        cout << mergeSort(cntinv, inv_u.sz) << '\n';
        x = u;
        while(x != -1) c[x] = c[v], x = p[x];
    }
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	int T = 1;
    ///cin >> T;
    while(T--) solve(), cout << '\n';
    return 0;
}

Compilation message (stderr)

construction.cpp: In function 'void solve()':
construction.cpp:88:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   88 |         for(int j = 0; j < inv_u.sz; ++j) cntinv[j] = inv_u[j];
      |                          ^

• Subtask 1: 7 / 7
• Subtask 2: 9 / 9
• Subtask 3: 0 / 84