Submission #320158

# Submission time Handle Problem Language Result Execution time Memory
320158 2020-11-07T19:14:53 Z ant101 Usmjeri (COCI17_usmjeri) C++14
28 / 140
1226 ms 222600 KB
#include <iostream>
#include <algorithm>
#include <cstring>
#include <iomanip>
#include <fstream>
#include <cmath>
#include <vector>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <map>
#include <stack>
#include <queue>
#include <assert.h>
#include <limits>
#include <cstdio>
#include <complex>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef double db;
typedef string str;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;
#define mp make_pair
#define f first
#define s second

typedef vector<int> vi;
typedef vector<ll> vl;
typedef vector<ld> vd;
typedef vector<str> vs;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<pd> vpd;

#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend()
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pf push_front
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353; // = (119<<23)+1
const int MX = 3e5+5;
const ll INF = 1e18;
const ld PI = 4*atan((ld)1);
const int dx[4] = {0,1,0,-1}, dy[4] = {1,0,-1,0};


namespace io {
    void setIn(string s) { freopen(s.c_str(),"r",stdin); }
    void setOut(string s) { freopen(s.c_str(),"w",stdout); }
    void setIO(string s = "") {
        ios_base::sync_with_stdio(0); cin.tie(0); // fast I/O
        // cin.exceptions(cin.failbit); // ex. throws exception when you try to read letter into int
        if (sz(s)) {
            setIn(s+".in");
            setOut(s+".out");
        } // for USACO
    }
}

using namespace io;

namespace input {
    template<class T> void re(complex<T>& x);
    template<class T1, class T2> void re(pair<T1,T2>& p);
    template<class T> void re(vector<T>& a);
    template<class T, size_t SZ> void re(array<T,SZ>& a);
    
    template<class T> void re(T& x) { cin >> x; }
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    template<class Arg, class... Args> void re(Arg& first, Args&... rest) {
        re(first); re(rest...);
    }
    
    template<class T> void re(complex<T>& x) { T a,b; re(a,b); x = cd(a,b); }
    template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
    template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
}

namespace output {
    template<class T1, class T2> void pr(const pair<T1,T2>& x);
    template<class T, size_t SZ> void pr(const array<T,SZ>& x);
    template<class T> void pr(const vector<T>& x);
    template<class T> void pr(const set<T>& x);
    template<class T1, class T2> void pr(const map<T1,T2>& x);
    
    template<class T> void pr(const T& x) { cout << x; }
    template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) {
        pr(first); pr(rest...);
    }
    
    template<class T1, class T2> void pr(const pair<T1,T2>& x) {
        pr("{",x.f,", ",x.s,"}");
    }
    template<class T> void prContain(const T& x) {
        pr("{");
        bool fst = 1; for (const auto& a: x) pr(!fst?", ":"",a), fst = 0; // const needed for vector<bool>
        pr("}");
    }
    template<class T, size_t SZ> void pr(const array<T,SZ>& x) { prContain(x); }
    template<class T> void pr(const vector<T>& x) { prContain(x); }
    template<class T> void pr(const set<T>& x) { prContain(x); }
    template<class T1, class T2> void pr(const map<T1,T2>& x) { prContain(x); }
    
    void ps() { pr("\n"); }
    template<class Arg> void ps(const Arg& first) {
        pr(first); ps(); // no space at end of line
    }
    template<class Arg, class... Args> void ps(const Arg& first, const Args&... rest) {
        pr(first," "); ps(rest...); // print w/ spaces
    }
}

using namespace output;

using namespace input;

ll add(ll a, ll b) {
    a += b;
    if(a >= MOD) {
        a -= MOD;
    }
    return a;
}
ll sub(ll a, ll b) {
    a -= b;
    if(a < 0) {
        a += MOD;
    }
    return a;
}

ll mul(ll a, ll b) {
    return (a * b)%MOD;
}

void add_self(ll& a, ll b) {
    a = add(a, b);
}
void sub_self(ll& a, ll b) {
    a = sub(a, b);
}
void mul_self(ll& a, ll b) {
    a = mul(a, b);
}

ll N, M;

ll l;
vector<ll> adj[MX];

ll timer;
vector<ll> tin, tout;
vector<vector<ll>> up;
vpl lcapz[MX];
ll postorder[MX];
ll curr = 0;
ll parent[MX];
ll mustequal[MX];
ll pref[MX];
set<pl> childsets[MX];
ll currpref[MX];
ll t = 0;
ll starttime[MX];
ll dp[MX][2];

void dfs(ll v, ll p)
{
    tin[v] = ++timer;
    up[v][0] = p;
    for (ll i = 1; i <= l; ++i)
        up[v][i] = up[up[v][i-1]][i-1];
    
    for (ll u : adj[v]) {
        if (u != p)
            dfs(u, v);
    }
    
    tout[v] = ++timer;
}

bool is_ancestor(ll u, ll v)
{
    return tin[u] <= tin[v] && tout[u] >= tout[v];
}

ll lca(ll u, ll v)
{
    if (is_ancestor(u, v))
        return u;
    if (is_ancestor(v, u))
        return v;
    for (ll i = l; i >= 0; --i) {
        if (!is_ancestor(up[u][i], v))
            u = up[u][i];
    }
    return up[u][0];
}

void preprocess(ll root) {
    tin.resize(N);
    tout.resize(N);
    timer = 0;
    l = ceil(log2(N));
    up.assign(N, vector<ll>(l + 1));
    dfs(root, root);
}

void precdfs(ll u, ll p) {
    starttime[u] = t++;
    parent[u] = p;
//    ps("indfs", u);
    trav (v, adj[u]) {
        if (v != p) {
            childsets[u].insert({t, v});
            precdfs(v, u);
        }
    }
//    ps("children", u);
//    trav(a, childsets[u]) {
//        ps(a);
//    }
//    ps();
    postorder[curr++] = u;
}

map<ll, pl> combs;
map<ll, ll> vis;
vl auxadj[MX];

pl color(ll u, ll p, ll order) {
    pl ret = combs[u];
    vis[u] = order;
    if (order) {
        swap(ret.f, ret.s);
    }
    trav (v, auxadj[u]) {
        if (v != p) {
            if (vis.count(v)) {
                if (vis[v] == vis[u]) {
                    return {0, 0};
                } else {
                    continue;
                }
            }
            pl val = color(v, u, 1-order);
            ret = {mul(ret.f, val.f), mul(ret.s, val.s)};
        }
    }
    return ret;
}

ll f(ll u, ll ud, ll p) {
    if (dp[u][ud] != -1) {
        return dp[u][ud];
    }
    dp[u][ud] = 1;
    map<ll, pl> ccombs;
    trav (v, adj[u]) {
        if (v != p) {
            if (mustequal[v] && p != -1) {
                if (ud) {
                    ccombs[v] = {0, f(v, 1, u)};
                } else {
                    ccombs[v] = {f(v, 0, u), 0};
                }
            } else {
                ccombs[v] = {f(v, 0, u), f(v, 1, u)};
            }
        }
    }
    combs.clear();
    vis.clear();
    combs = ccombs;
    trav(c, lcapz[u]) {
        set<pl>::iterator p1 = childsets[u].upper_bound({starttime[c.f], 1e13});
        set<pl>::iterator p2 = childsets[u].upper_bound({starttime[c.s], 1e13});
//        ps(starttime[c.f], starttime[c.s], *p1, *p2);
        ll a, b;
        if (p1 == childsets[u].begin() || p2 == childsets[u].begin()) {
            continue;
        }
        --p1;
        --p2;
        a = (*p1).s;
        b = (*p2).s;
        auxadj[a].pb(b);
        auxadj[b].pb(a);
    }
    trav (v, adj[u]) {
        if (v != p && !vis.count(v)) {
            pl val = color(v, u, 0);
            dp[u][ud] = mul(dp[u][ud], add(val.f, val.s));
        }
    }
    trav(c, lcapz[u]) {
        set<pl>::iterator p1 = childsets[u].upper_bound({starttime[c.f], 1e13});
        set<pl>::iterator p2 = childsets[u].upper_bound({starttime[c.s], 1e13});
        ll a, b;
        if (p1 == childsets[u].begin() || p2 == childsets[u].begin()) {
            continue;
        }
        --p1;
        --p2;
        a = (*p1).s;
        b = (*p2).s;
        auxadj[a].clear();
        auxadj[b].clear();
    }
//    ps(u, ud, dp[u][ud]);
    return dp[u][ud];
}



int main() {
//    setIn("usmjeri.in.3a");
    memset(dp, -1, sizeof(dp));
    re(N, M);
    F0R (i, N-1) {
        ll a, b;
        re(a, b);
        a--;
        b--;
        adj[a].pb(b);
        adj[b].pb(a);
    }
    preprocess(0);
    F0R (i, M) {
        ll a, b;
        re(a, b);
        a--;
        b--;
        ll node = lca(a, b);
        lcapz[node].pb({a, b});
//        ps(node, a, b);
    }
    precdfs(0, -1);
    F0R (i, N) {
        trav(a, lcapz[i]) {
            pref[a.f]++;
            pref[a.s]++;
            set<pl>::iterator p1 = childsets[i].upper_bound({a.f, 1e13});
            set<pl>::iterator p2 = childsets[i].upper_bound({a.s, 1e13});
            ll b, c;
            if (p1 == childsets[i].begin()) {
                b = a.f;
            } else {
                --p1;
                b = (*p1).s;
            }
            if (p2 == childsets[i].begin()) {
                c = a.s;
            } else {
                --p2;
                c = (*p2).s;
            }
            pref[b]--;
            pref[c]--;
        }
//        ps("pref", i, pref[i]);
    }
    F0R (i, curr) {
        ll v = postorder[i];
//        ps(v);
        currpref[v]+=pref[v];
        currpref[parent[v]]+=currpref[v];
        mustequal[v] = (currpref[v] != 0);
//        if (mustequal[v]) {
//            ps("set", v);
//        }
    }
    ps(f(0, 1, -1));
    return 0;
}

Compilation message

usmjeri.cpp: In function 'void io::setIn(std::string)':
usmjeri.cpp:67:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   67 |     void setIn(string s) { freopen(s.c_str(),"r",stdin); }
      |                            ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
usmjeri.cpp: In function 'void io::setOut(std::string)':
usmjeri.cpp:68:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   68 |     void setOut(string s) { freopen(s.c_str(),"w",stdout); }
      |                             ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 326 ms 102884 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 806 ms 222600 KB Output is correct
# Verdict Execution time Memory Grader output
1 Incorrect 29 ms 40684 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 32 ms 40552 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 39 ms 42084 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 39 ms 42092 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 1050 ms 158424 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 1226 ms 161628 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 1121 ms 162412 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 1106 ms 163240 KB Output isn't correct
2 Halted 0 ms 0 KB -