Submission #419716

#	Time	Username	Problem	Language	Result	Execution time	Memory
419716		NintsiChkhaidze	Zagrade (COI17_zagrade)	C++14	40 / 100	626 ms	64544 KiB

zagrade

#include <bits/stdc++.h>
#define pb push_back
#define ll long long
#define left (node<<1),l,(l+r)>>1
#define right ((node<<1)|1),((l+r)>>1) + 1,r
using namespace std;
const int N = 300005;
int A[N],S[N],Q,dp[N],t[4*N],n;
ll res;
vector <int> v[N];
map <int,int> last;
void upd(int node,int l,int r,int idx,int val){
    if (l == r) {t[node] = val; return;}
    if (idx > ((l+r)>>1)) upd(right,idx,val);
    else upd(left,idx,val);
    t[node] = min(t[node<<1],t[((node<<1)|1)]);
}
int get(int node,int l,int r,int L,int R){
    if (r < L || R  < l) return 1e9;
    if (L <= l && r <= R) return t[node];
    int x = get(left,L,R),y = get(right,L,R);
    return min(x,y);
}
void dfs(int x,int par){
    A[x] = A[par] + S[x];
    upd(1,1,n,x,A[x]);
    
    if (last[A[x]]){
        int id = last[A[x]];
        int mn = get(1,1,n,id + 1,x) - A[x];
        if (mn == 0) dp[x] = dp[id] + 1,res+=dp[x];
    }
    else if (A[x] == 0){
        int mn = get(1,1,n,1,x);
        if (mn == 0) dp[x] = 1,res+=dp[x];
    }
    last[A[x]] = x;
    for (int j=0;j<v[x].size();j++)
        if (v[x][j]!=par) dfs(v[x][j],x);
}
void dfs2(int x,int par){
    A[x] = A[par] + S[x];
    upd(1,1,n,x,A[x]);
    
    if (last[A[x]]){
        int id = last[A[x]];
        int mn = get(1,1,n,x,id-1) - A[x];
        if (mn == 0) dp[x] = dp[id] + 1,res+=dp[x];
    }
    else if (A[x] == 0){
        int mn = get(1,1,n,x,n);
        if (mn == 0) dp[x] = 1,res+=dp[x];
    }
    last[A[x]] = x;
    for (int j=0;j<v[x].size();j++)
        if (v[x][j]!=par) dfs2(v[x][j],x);
}
void DFS(int x,int par){
    A[x] = A[par] + S[x];
    if (A[x] == 0) res++;
    if (A[x] < 0) return;
    for (int j=0;j<v[x].size();j++){
        int to = v[x][j];
        if (to!=par && A[to] >= 0) DFS(to,x);
    }
}
int main (){
    ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
    cin>>n;
    string s;
    cin>>s;
    
    s = '$' + s;
    for (int i=1;i<=n;i++)
        if (s[i] == '(') S[i] = 1;
        else S[i]= -1;
        
    for (int i=1;i<n;i++){
        int a,b;
        cin>>a>>b;
        v[a].pb(b),v[b].pb(a);
    }    

    if (n <= 1000){
        for (int i =1;i<=n;i++){
            if (S[i] == 1) DFS(i,i);
            for (int j=1;j<=n;j++)
                A[j] = 0;
        }
        cout<<res;
        return 0;
    }
    for (int i=1;i<=4*N;i++) 
        t[i] = 1e9;
        
    dfs(1,1);
    for (int i=1;i<=4*N;i++)
        t[i] = 1e9;
    for (int i=1;i<=n;i++) 
        dp[i] = 0,A[i]=0;
    
    last.clear();
    dfs2(n,n);
    cout<<res;
}

Compilation message (stderr)

zagrade.cpp: In function 'void dfs(int, int)':
zagrade.cpp:38:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |     for (int j=0;j<v[x].size();j++)
      |                  ~^~~~~~~~~~~~
zagrade.cpp: In function 'void dfs2(int, int)':
zagrade.cpp:55:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |     for (int j=0;j<v[x].size();j++)
      |                  ~^~~~~~~~~~~~
zagrade.cpp: In function 'void DFS(int, int)':
zagrade.cpp:62:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |     for (int j=0;j<v[x].size();j++){
      |                  ~^~~~~~~~~~~~
zagrade.cpp: In function 'int main()':
zagrade.cpp:94:14: warning: iteration 1200019 invokes undefined behavior [-Waggressive-loop-optimizations]
   94 |         t[i] = 1e9;
      |         ~~~~~^~~~~
zagrade.cpp:93:19: note: within this loop
   93 |     for (int i=1;i<=4*N;i++)
      |                  ~^~~~~
zagrade.cpp:98:14: warning: iteration 1200019 invokes undefined behavior [-Waggressive-loop-optimizations]
   98 |         t[i] = 1e9;
      |         ~~~~~^~~~~
zagrade.cpp:97:19: note: within this loop
   97 |     for (int i=1;i<=4*N;i++)
      |                  ~^~~~~

• Subtask 1: 10 / 10
• Subtask 2: 30 / 30
• Subtask 3: 0 / 60