Submission #407552

#	Time	Username	Problem	Language	Result	Execution time	Memory
407552		juggernaut	Street Lamps (APIO19_street_lamps)	C++17	100 / 100	3263 ms	199240 KiB

street_lamps

    #include <bits/stdc++.h>
    using namespace std;
    const int N=300050;
    const int M=18*18*N;
    int state[N];
    struct Seg
    {
    	int l,r,tme;
    	Seg(){}
    	Seg(int a, int b, int c):l(a),r(b),tme(c){}
    	bool operator < (Seg b) const { return l<b.l;}
    };
    set<Seg> all;
    Seg Get(int x)
    {
    	auto it=all.lower_bound(Seg(x+1,0,0));
    	it--;
    	return *it;
    }
    int root[N],ls[M],rs[M],tsz,sum[M];
    void Set(int &c, int ss, int se, int qs, int qe, int x)
    {
    	if(qs>qe || qs>se || ss>qe) return;
    	if(!c) c=++tsz;
    	if(qs<=ss && qe>=se){ sum[c]+=x;return;}
    	int mid=ss+se>>1;
    	Set(ls[c],ss,mid,qs,qe,x);
    	Set(rs[c],mid+1,se,qs,qe,x);
    }
    int Get(int c, int ss, int se, int qi)
    {
    	if(ss==se) return sum[c];
    	int mid=ss+se>>1;
    	if(qi<=mid) return sum[c]+Get(ls[c],ss,mid,qi);
    	else return sum[c]+Get(rs[c],mid+1,se,qi);
    }
    void Set(int qi, int l, int r, int x)
    {
    	for(int i=qi;i<N;i+=i&-i) Set(root[i],1,N,l,r,x);
    }
    void Set(int l, int r, int x)
    {
    	Set(l,l,r,x);
    	Set(r+1,l,r,-x);
    }
    int Get(int x, int y)
    {
    	int ans=0;
    	for(int i=x;i;i-=i&-i) ans+=Get(root[i],1,N,y);
    	return ans;
    }
    void Set(Seg sg, int tme)
    {
    	Set(sg.l,sg.r,tme-sg.tme);
    }
    void Update(int x, int tme)
    {
    	if(state[x])
    	{
    		Seg tmp=Get(x);
    		Set(tmp,tme);
    		all.erase(tmp);
    		all.insert(Seg(tmp.l,x,tme));
    		all.insert(Seg(x+1,tmp.r,tme));
    	}
    	else
    	{
    		Seg L=Get(x),R=Get(x+1);
    		Set(L,tme);
    		Set(R,tme);
    		all.erase(L);
    		all.erase(R);
    		all.insert(Seg(L.l,R.r,tme));
    	}
    	state[x]^=1;
    }
    char s[N];
    int main()
    {
    	int n,q;
    	scanf("%i %i",&n,&q);
    	scanf("%s",s+1);
    	for(int i=1;i<=n;i++) state[i]=s[i]=='1';
    	for(int i=1,j=1;i<=n+1;i=j+1)
    	{
    		for(j=i;j<=n && state[j];j++);
    		all.insert(Seg(i,j,0));
    	}
    	char t[10];
    	for(int i=1;i<=q;i++)
    	{
    		scanf("%s",t);
    		if(t[0]=='t')
    		{
    			int x;
    			scanf("%i",&x);
    			Update(x,i);
    		}
    		else
    		{
    			int a,b;
    			scanf("%i %i",&a,&b);
    			int ans=Get(a,b);
    			Seg tmp=Get(a);
    			if(tmp.r>=b) ans+=i-tmp.tme;
    			printf("%i\n",ans);
    		}
    	}
    	return 0;
    }

Compilation message (stderr)

street_lamps.cpp: In function 'void Set(int&, int, int, int, int, int)':
street_lamps.cpp:26:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   26 |      int mid=ss+se>>1;
      |              ~~^~~
street_lamps.cpp: In function 'int Get(int, int, int, int)':
street_lamps.cpp:33:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   33 |      int mid=ss+se>>1;
      |              ~~^~~
street_lamps.cpp: In function 'int main()':
street_lamps.cpp:81:11: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |      scanf("%i %i",&n,&q);
      |      ~~~~~^~~~~~~~~~~~~~~
street_lamps.cpp:82:11: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   82 |      scanf("%s",s+1);
      |      ~~~~~^~~~~~~~~~
street_lamps.cpp:92:12: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   92 |       scanf("%s",t);
      |       ~~~~~^~~~~~~~
street_lamps.cpp:96:13: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   96 |        scanf("%i",&x);
      |        ~~~~~^~~~~~~~~
street_lamps.cpp:102:13: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |        scanf("%i %i",&a,&b);
      |        ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20