Submission #1102845

#	Time	Username	Problem	Language	Result	Execution time	Memory
1102845		_rain_	Islands (IOI08_islands)	C++14	80 / 100	529 ms	131072 KiB

islands

#include<bits/stdc++.h>
using namespace std;
 #pragma GCC optimize(Ofast)
    #pragma GCC optimization (unroll-loops)
    #pragma GCC target(avx,avx2,fma)
    #pragma GCC target(sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native)
    #pragma GCC optimize(3)
    #pragma GCC optimize("inline")
    #pragma GCC optimize("-fgcse")
    #pragma GCC optimize("-fgcse-lm")
    #pragma GCC optimize("-fipa-sra")
    #pragma GCC optimize("-ftree-pre")
    #pragma GCC optimize("-ftree-vrp")
    #pragma GCC optimize("-fpeephole2")
    #pragma GCC optimize("-ffast-math")
    #pragma GCC optimize("-fsched-spec")
    #pragma GCC optimize("unroll-loops")
    #pragma GCC optimize("-falign-jumps")
    #pragma GCC optimize("-falign-loops")
    #pragma GCC optimize("-falign-labels")
    #pragma GCC optimize("-fdevirtualize")
    #pragma GCC optimize("-fcaller-saves")
    #pragma GCC optimize("-fcrossjumping")
    #pragma GCC optimize("-fthread-jumps")
    #pragma GCC optimize("-funroll-loops")
    #pragma GCC optimize("-fwhole-program")
    #pragma GCC optimize("-freorder-blocks")
    #pragma GCC optimize("-fschedule-insns")
    #pragma GCC optimize("inline-functions")
    #pragma GCC optimize("-ftree-tail-merge")
    #pragma GCC optimize("-fschedule-insns2")
    #pragma GCC optimize("-fstrict-aliasing")
    #pragma GCC optimize("-fstrict-overflow")
    #pragma GCC optimize("-falign-functions")
    #pragma GCC optimize("-fcse-skip-blocks")
    #pragma GCC optimize("-fcse-follow-jumps")
    #pragma GCC optimize("-fsched-interblock")
    #pragma GCC optimize("-fpartial-inlining")
    #pragma GCC optimize("no-stack-protector")
    #pragma GCC optimize("-freorder-functions")
    #pragma GCC optimize("-findirect-inlining")
    #pragma GCC optimize("-fhoist-adjacent-loads")
    #pragma GCC optimize("-frerun-cse-after-loop")
    #pragma GCC optimize("inline-small-functions")
    #pragma GCC optimize("-finline-small-functions")
    #pragma GCC optimize("-ftree-switch-conversion")
    #pragma GCC optimize("-foptimize-sibling-calls")
    #pragma GCC optimize("-fexpensive-optimizations")
    #pragma GCC optimize("-funsafe-loop-optimizations")
    #pragma GCC optimize("inline-functions-called-once")
    #pragma GCC optimize("-fdelete-null-pointer-checks")
#define name "main"
typedef long long ll;
typedef pair<int,int> ii;
#define fi first
#define se second
 
const int N = (int)1e6;
vector<ii> ke[N+2];
int cost[N+2],gi[N+2],vis[N+2],n,cha[N+2],arr[N+2],sz=0,times=0;
ll dep[N*2+2]={},pre[N*2+2]={},f[N*2+2]={};
bool com[N+2];
void add_edge(int u , int v , int w){
	ke[u].push_back({v,w});
	ke[v].push_back({u,w});
}
void search(int u , int p){
	vis[u] = ++times;
	for (auto& x:ke[u]){
		int v=x.fi,w=x.se;
		if (v==p) continue;
		if (!vis[v]) {
			cha[v]=u;
			gi[v]=w;
			search(v,u);
		}
		else{
			if (vis[v]<vis[u]) continue;
			++sz;
			arr[sz]=v;cost[sz]=w;
			for (; v!=u; v=cha[v]){
				++sz;
				arr[sz]=cha[v];
				cost[sz]=gi[v];
			}
		}
	}
	return ;
}
// the component has at most 1 cycle inside ~
ll mx,ans=0;
int pos,root;
void dfs(int u , int p , ll s){
	if (mx < s){
		mx = s;
		pos = u;
	}
	for (auto& x:ke[u]){
		int v=x.fi,w=x.se;
		if ((com[v]&&v!=root)||v==p) continue;
		dfs(v,u,s+w);
	}
	return;
}
 
int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);
 
	cin>>n;
	for (int i=1; i<=n; ++i){
		int en,l; cin>>en>>l;
		ke[i].push_back({en,l});
		ke[en].push_back({i,l});
	}
	for (int id=1; id<=n; ++id){
		if (!vis[id]){
			sz = times = 0;
			search(id,id);
			ll addmore = -1;
			for (int i = 1; i <= sz; ++i) com[arr[i]] = true;
			for (int i = 1; i <= sz; ++i){
				mx=pos=root=-1;
				dfs(arr[i],0,0);
				dep[i]=mx;
				root=arr[i];
				dfs(pos,0,0);
				addmore = max(addmore,mx);
				pre[i]=pre[i-1]+cost[i];
			}
			for (int i = sz + 1; i <= sz*2; ++i){
				cost[i] = cost[i-sz];
				dep[i] = dep[i-sz];
				pre[i]=pre[i-1]+cost[i];
			}
			for (int i=1; i<=sz*2; ++i) f[i]=dep[i]-pre[i];
			deque<int> q;
			for (int i = 1; i <= sz*2; ++i){
				while (q.size() && q.front()<i-sz+1) q.pop_front();
				if (q.size()){
					addmore = max(addmore,pre[i]+dep[i]+f[q.front()]);
				}
				while (q.size() && f[q.back()]<=f[i]) q.pop_back();	
				q.push_back(i);
			}
			ans+=addmore;
		}
	}
	cout<<ans;
	exit(0);
}

Compilation message (stderr)

islands.cpp:4: warning: ignoring '#pragma GCC optimization' [-Wunknown-pragmas]
    4 |     #pragma GCC optimization (unroll-loops)
      | 
islands.cpp:3:23: warning: '#pragma GCC optimize' is not a string or number [-Wpragmas]
    3 |  #pragma GCC optimize(Ofast)
      |                       ^~~~~
islands.cpp:5:24: warning: '#pragma GCC option' is not a string [-Wpragmas]
    5 |     #pragma GCC target(avx,avx2,fma)
      |                        ^~~
islands.cpp:6:24: warning: '#pragma GCC option' is not a string [-Wpragmas]
    6 |     #pragma GCC target(sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,tune=native)
      |                        ^~~
islands.cpp:26:43: warning: bad option '-fwhole-program' to pragma 'optimize' [-Wpragmas]
   26 |     #pragma GCC optimize("-fwhole-program")
      |                                           ^
islands.cpp:33:45: warning: bad option '-fstrict-overflow' to pragma 'optimize' [-Wpragmas]
   33 |     #pragma GCC optimize("-fstrict-overflow")
      |                                             ^
islands.cpp:35:45: warning: bad option '-fcse-skip-blocks' to pragma 'optimize' [-Wpragmas]
   35 |     #pragma GCC optimize("-fcse-skip-blocks")
      |                                             ^
islands.cpp:49:55: warning: bad option '-funsafe-loop-optimizations' to pragma 'optimize' [-Wpragmas]
   49 |     #pragma GCC optimize("-funsafe-loop-optimizations")
      |                                                       ^
islands.cpp:63:36: warning: bad option '-fwhole-program' to attribute 'optimize' [-Wattributes]
   63 | void add_edge(int u , int v , int w){
      |                                    ^
islands.cpp:63:36: warning: bad option '-fstrict-overflow' to attribute 'optimize' [-Wattributes]
islands.cpp:63:36: warning: bad option '-fcse-skip-blocks' to attribute 'optimize' [-Wattributes]
islands.cpp:63:36: warning: bad option '-funsafe-loop-optimizations' to attribute 'optimize' [-Wattributes]
islands.cpp:67:26: warning: bad option '-fwhole-program' to attribute 'optimize' [-Wattributes]
   67 | void search(int u , int p){
      |                          ^
islands.cpp:67:26: warning: bad option '-fstrict-overflow' to attribute 'optimize' [-Wattributes]
islands.cpp:67:26: warning: bad option '-fcse-skip-blocks' to attribute 'optimize' [-Wattributes]
islands.cpp:67:26: warning: bad option '-funsafe-loop-optimizations' to attribute 'optimize' [-Wattributes]
islands.cpp:93:30: warning: bad option '-fwhole-program' to attribute 'optimize' [-Wattributes]
   93 | void dfs(int u , int p , ll s){
      |                              ^
islands.cpp:93:30: warning: bad option '-fstrict-overflow' to attribute 'optimize' [-Wattributes]
islands.cpp:93:30: warning: bad option '-fcse-skip-blocks' to attribute 'optimize' [-Wattributes]
islands.cpp:93:30: warning: bad option '-funsafe-loop-optimizations' to attribute 'optimize' [-Wattributes]
islands.cpp:106:14: warning: bad option '-fwhole-program' to attribute 'optimize' [-Wattributes]
  106 | int32_t main(){
      |              ^
islands.cpp:106:14: warning: bad option '-fstrict-overflow' to attribute 'optimize' [-Wattributes]
islands.cpp:106:14: warning: bad option '-fcse-skip-blocks' to attribute 'optimize' [-Wattributes]
islands.cpp:106:14: warning: bad option '-funsafe-loop-optimizations' to attribute 'optimize' [-Wattributes]

• Subtask 1: 33 / 33
• Subtask 2: 3 / 3
• Subtask 3: 4 / 4
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10