Submission #1694622

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Source Code Expand

#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define mt make_tuple
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
#define pb push_back
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

int N, E[150000][2], frm[150001];
vi G[150000];
double dp[150001][2], sm[150001];

double f(int e, int s) {
    double &res = dp[e][s];
    if (res > -1)return res;
    int u = E[e][s];
    res = 0;
    if (sz(G[u]) == 1)return res;
    double p = 1.0 / (sz(G[u]) - 1);

    if (sm[u] > -1) {
        res = sm[u] + (f(frm[u], E[frm[u]][0] == u) - f(e, !s))*p;
        return res;
    }

    each(ne, G[u])if (ne != e) {
        res += f(ne, E[ne][0] == u);
    }
    res = res*p + 1.0;
    sm[u] = res;
    frm[u] = e;
    return res;
}

int main() {
    scanf("%d", &N);
    rep(i, N - 1) {
        int u, v;
        scanf("%d%d", &u, &v);
        --u; --v;
        E[i][0] = u;
        E[i][1] = v;
        G[u].push_back(i);
        G[v].push_back(i);
    }

    rep(i, N) {
        sm[i] = -2;
        rep(j, 2)dp[i][j] = -2;
    }
    rep(i, N) {
        double ans = 0, p = -1;
        if (sz(G[i]))p = 1.0 / sz(G[i]);
        each(e, G[i]) {
            ans += f(e, E[e][0] == i);
        }
        if (sz(G[i]))ans = ans*p + 1;
        printf("%.8f\n", ans);
    }
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:47:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &N);
                    ^
./Main.cpp:50:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d", &u, &v);
                              ^

Judge Result