Submission #378317

#	Time	Username	Problem	Language	Result	Execution time	Memory
378317		mihai145	Election Campaign (JOI15_election_campaign)	C++14	0 / 100	180 ms	20900 KiB

election_campaign

#include <iostream>
#include <vector>

using namespace std;

const int NMAX = 1e5;
const int LGMAX = 17;

struct ElectoralRoad {
    int x, y, c;
};

int N, M;
vector <int> g[NMAX + 2];
vector <ElectoralRoad> lca[NMAX + 2];

int h[NMAX + 2], dp[NMAX + 2], dpSons[NMAX + 2];
int anc[NMAX + 2][LGMAX + 2];

void dfs(int node, int parent = 0) {
    anc[node][0] = parent;

    for(int son : g[node]) {
        if(son != parent) {
            h[son] = h[node] + 1;
            dfs(son, node);
        }
    }
}

void BinaryLift() {
    for(int step = 1; step <= LGMAX; step++) {
        for(int i = 1; i <= N; i++) {
            anc[i][step] = anc[anc[i][step - 1]][step - 1];
        }
    }
}

int getLca(int x, int y) {
    if(h[x] < h[y]) {
        swap(x, y);
    }

    for(int step = LGMAX; step >= 0; step--) {
        if(h[anc[x][step]] >= h[y]) {
            x = anc[x][step];
        }
    }

    if(x == y) {
        return x;
    }

    for(int step = LGMAX; step >= 0; step--) {
        if(anc[x][step] != anc[y][step]) {
            x = anc[x][step];
            y = anc[y][step];
        }
    }

    return anc[x][0];
}

void solve(int node, int parent = 0) {
    int sumDpSon = 0;

    for(int son : g[node]) {
        if(son != parent) {
            solve(son, node);
            sumDpSon += dp[son];
        }
    }

    for(int i = LGMAX; i >= 1; i--) {
        dpSons[node] = sumDpSon;
    }


    /*
    for(ElectoralRoad road : lca[node]) {
        int newDp = road.c;
        pair <int, int> crossedKids;

        if(node != road.x) {

        }

        if(node != road.y) {

        }

        dp[node] = max(dp[node], newDp);
    }
    */

    dp[node] = max(dp[node], dpSons[node]);
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    cin >> N;

    for(int i = 1; i < N; i++) {
        int x, y;
        cin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }

    h[1] = 1;
    dfs(1);
    BinaryLift();

    cin >> M;

    for(int i = 1; i <= M; i++) {
        int x, y, c;
        cin >> x >> y >> c;

        lca[getLca(x, y)].push_back({x, y, c});
    }

    solve(1);


    return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 5
• Subtask 3: 0 / 5
• Subtask 4: 0 / 30
• Subtask 5: 0 / 10
• Subtask 6: 0 / 40