oj.uz

Submission #246947

# Submission time Handle Problem Language Result Execution time Memory
246947 2020-07-10T15:56:26 Z rqi Beads and wires (APIO14_beads) C++14
28 / 100
 1000 ms 5632 KB 
#include <bits/stdc++.h>
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<db,db> pd; 

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

#define mp make_pair
#define f first
#define s second
#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;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

template<class T> bool ckmin(T& a, const T& b) { 
    return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
    return a < b ? a = b, 1 : 0; } 
int pct(int x) { return __builtin_popcount(x); } 
int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 
int fstTrue(function<bool(int)> f, int lo, int hi) {
    hi ++; assert(lo <= hi); // assuming f is increasing
    while (lo < hi) { // find first index such that f is true 
        int mid = (lo+hi)/2; 
        f(mid) ? hi = mid : lo = mid+1; 
    } 
    return lo;
}

// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);

template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }

template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
template<class A> str ts(complex<A> c) { 
    stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) { 
    str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
    res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
    str res = ""; F0R(i,SZ) res += char('0'+b[i]);
    return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
    bool fst = 1; str res = "{";
    for (const auto& x: v) {
        if (!fst) res += ", ";
        fst = 0; res += ts(x);
    }
    res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
    return "("+ts(p.f)+", "+ts(p.s)+")"; }

// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
    pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
    pr(h); if (sizeof...(t)) pr(" "); ps(t...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << ts(h); if (sizeof...(t)) cerr << ", ";
    DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif

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

const int mx = 200005;

int n;
vpi adj[mx]; // node, dist

int dp[mx][2]; //filled everything up, 1 blue hanging from root

void ndfs(int node, int prv = -1){
    for(auto u: adj[node]){
        if(u.f == prv) continue;
        ndfs(u.f, node);
    }
    dp[node][0] = 0;

    for(auto u: adj[node]){
        if(u.f == prv) continue;
        dp[node][0]+=max(u.s+dp[u.f][1], dp[u.f][0]);
    }
    dp[node][1] = -2*MOD;
    for(auto u: adj[node]){
        if(u.f == prv) continue;
        ckmax(dp[node][1], dp[node][0]-max(u.s+dp[u.f][1], dp[u.f][0])+u.s+dp[u.f][0]);
    }
    //dbg(node, dp[node][0]);
}

int naivesolve(int R){
    //dbg(R);
    for(int i = 1; i <= n; i++){
        dp[i][0] = dp[i][1] = -2*MOD;
    }
    ndfs(R);
    return dp[R][0]; 
}

int main() {
    setIO();
    
    cin >> n;
    for(int i = 1; i <= n-1; i++){
        int a, b, c;
        cin >> a >> b >> c;
        adj[a].pb(mp(b, c));
        adj[b].pb(mp(a, c));
    }

    int ans = 0;

    for(int i = 1; i <= n; i++){
        //dbg(i, naivesolve(i));
        ckmax(ans, naivesolve(i));
    }

    ps(ans);

    // you should actually read the stuff at the bottom
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?)
    * do smth instead of nothing and stay organized
    * WRITE STUFF DOWN
*/

Compilation message

beads.cpp: In function 'void setIn(std::__cxx11::string)':
beads.cpp:128:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
beads.cpp: In function 'void setOut(std::__cxx11::string)':
beads.cpp:129:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5120 KB Output is correct
2 Correct 7 ms 4992 KB Output is correct
3 Correct 7 ms 4992 KB Output is correct
4 Correct 8 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 5120 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 7 ms 5120 KB Output is correct
10 Correct 7 ms 4992 KB Output is correct
11 Correct 8 ms 5120 KB Output is correct
12 Correct 7 ms 4992 KB Output is correct

Subtask #2
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5120 KB Output is correct
2 Correct 7 ms 4992 KB Output is correct
3 Correct 7 ms 4992 KB Output is correct
4 Correct 8 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 5120 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 7 ms 5120 KB Output is correct
10 Correct 7 ms 4992 KB Output is correct
11 Correct 8 ms 5120 KB Output is correct
12 Correct 7 ms 4992 KB Output is correct
13 Correct 7 ms 4992 KB Output is correct
14 Correct 7 ms 4992 KB Output is correct
15 Correct 7 ms 4992 KB Output is correct
16 Correct 8 ms 5120 KB Output is correct
17 Correct 10 ms 5120 KB Output is correct
18 Correct 8 ms 5120 KB Output is correct
19 Correct 8 ms 5120 KB Output is correct
20 Correct 9 ms 5120 KB Output is correct
21 Correct 8 ms 5120 KB Output is correct
22 Correct 8 ms 4992 KB Output is correct

Subtask #3
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5120 KB Output is correct
2 Correct 7 ms 4992 KB Output is correct
3 Correct 7 ms 4992 KB Output is correct
4 Correct 8 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 5120 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 7 ms 5120 KB Output is correct
10 Correct 7 ms 4992 KB Output is correct
11 Correct 8 ms 5120 KB Output is correct
12 Correct 7 ms 4992 KB Output is correct
13 Correct 7 ms 4992 KB Output is correct
14 Correct 7 ms 4992 KB Output is correct
15 Correct 7 ms 4992 KB Output is correct
16 Correct 8 ms 5120 KB Output is correct
17 Correct 10 ms 5120 KB Output is correct
18 Correct 8 ms 5120 KB Output is correct
19 Correct 8 ms 5120 KB Output is correct
20 Correct 9 ms 5120 KB Output is correct
21 Correct 8 ms 5120 KB Output is correct
22 Correct 8 ms 4992 KB Output is correct
23 Correct 866 ms 5384 KB Output is correct
24 Correct 838 ms 5472 KB Output is correct
25 Correct 861 ms 5496 KB Output is correct
26 Execution timed out 1091 ms 5632 KB Time limit exceeded
27 Halted 0 ms 0 KB -

Subtask #4
0 / 43.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 5120 KB Output is correct
2 Correct 7 ms 4992 KB Output is correct
3 Correct 7 ms 4992 KB Output is correct
4 Correct 8 ms 4992 KB Output is correct
5 Correct 7 ms 4992 KB Output is correct
6 Correct 7 ms 5120 KB Output is correct
7 Correct 7 ms 4992 KB Output is correct
8 Correct 7 ms 5120 KB Output is correct
9 Correct 7 ms 5120 KB Output is correct
10 Correct 7 ms 4992 KB Output is correct
11 Correct 8 ms 5120 KB Output is correct
12 Correct 7 ms 4992 KB Output is correct
13 Correct 7 ms 4992 KB Output is correct
14 Correct 7 ms 4992 KB Output is correct
15 Correct 7 ms 4992 KB Output is correct
16 Correct 8 ms 5120 KB Output is correct
17 Correct 10 ms 5120 KB Output is correct
18 Correct 8 ms 5120 KB Output is correct
19 Correct 8 ms 5120 KB Output is correct
20 Correct 9 ms 5120 KB Output is correct
21 Correct 8 ms 5120 KB Output is correct
22 Correct 8 ms 4992 KB Output is correct
23 Correct 866 ms 5384 KB Output is correct
24 Correct 838 ms 5472 KB Output is correct
25 Correct 861 ms 5496 KB Output is correct
26 Execution timed out 1091 ms 5632 KB Time limit exceeded
27 Halted 0 ms 0 KB -