Submission #42209585

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Source Code Expand

#include<cstdio>
#include<cstring>
#include<algorithm>
#define N 210000
#define M 410000
#define MM 810000
#define fep(i,x,y) for(int i=x;i<=y;i++)
#define feq(i,x,y) for(int i=x;i>=y;i--)
using namespace std;
typedef long long LL;
template<class T> 
inline T mymin(T x,T y){return x<y?x:y;}
template<class T>
inline T mymax(T x,T y){return x>y?x:y;}
struct node{
	int lc,rc;
	LL k1,k2;
}tr[MM];int len;
inline void updata(int x){
	tr[x].k1=mymax(tr[tr[x].lc].k1,tr[tr[x].rc].k1);
	tr[x].k2=mymax(tr[tr[x].lc].k2,tr[tr[x].rc].k2);
}
void bt(int l,int r){
	int x=++len;
	tr[x].k1=tr[x].k2=-999999999;
	if(l<r){
		int mid=(l+r)>>1;
		tr[x].lc=len+1;bt(l,mid);
		tr[x].rc=len+1;bt(mid+1,r);
	}
}
LL findans(int x,int l,int r,int ll,int rr,int type){
	if(r<ll || l>rr)return -999999999;
	if(ll<=l && rr>=r)return type==1?tr[x].k1:tr[x].k2;
	int mid=(l+r)>>1;
	return mymax(findans(tr[x].lc,l,mid,ll,rr,type),findans(tr[x].rc,mid+1,r,ll,rr,type));
}
void change(int x,int l,int r,int id,LL k,int type){
	if(l==r){
		if(type==1)tr[x].k1=mymax(tr[x].k1,k);
		else tr[x].k2=mymax(tr[x].k2,k);
		return ;
	}
	int mid=(l+r)>>1;
	if(id<=mid)change(tr[x].lc,l,mid,id,k,type);
	else change(tr[x].rc,mid+1,r,id,k,type);
	updata(x);
}
int a[N],b[N],*id[M],n,m,be[M];
inline bool cmp(int *x,int *y){return (*x)<(*y);}
int main(){
	scanf("%d",&n);
	fep(i,1,n){
		scanf("%d%d",&a[i],&b[i]);
		id[i]=&a[i];id[i+n]=&b[i];
	}
	sort(id+1,id+n+n+1,cmp);
	m=1;
	fep(i,1,n+n){
		if((*id[i])!=be[m])be[++m]=(*id[i]);
		(*id[i])=m;
	}
	bt(1,m);
	change(1,1,m,1,0,1);
	LL zans=0;
	fep(i,1,n){
		LL ans=mymax(findans(1,1,m,1,a[i]-1,1)+be[b[i]]-be[a[i]]+1,findans(1,1,m,a[i],b[i],2)+be[b[i]]);
		change(1,1,m,b[i],ans,1);
		change(1,1,m,b[i],ans-be[b[i]],2);
		zans=mymax(zans,ans);
	}
	printf("%lld\n",zans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:52:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   52 |  scanf("%d",&n);
      |  ~~~~~^~~~~~~~~
./Main.cpp:54:8: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   54 |   scanf("%d%d",&a[i],&b[i]);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~

Judge Result