Submission #8399459

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Source Code Expand

#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define N 400010
#define mod 1000000007
#define ll long long
using namespace std;
ll tree[N<<2];
void insert(int u,int l,int r,int p,int v)
{
	if(l==r){tree[u]=(tree[u]+v)%mod;return;}
	int mid=(l+r)>>1;
	if(p<=mid) insert(u<<1,l,mid,p,v);
	else insert(u<<1|1,mid+1,r,p,v);
	tree[u]=tree[u<<1]+tree[u<<1|1];
}
ll answer(int u,int l,int r,int L,int R)
{
	if(L<=l && r<=R) return tree[u];
	int mid=(l+r)>>1;
	ll ans=0;
	if(L<=mid) ans+=answer(u<<1,l,mid,L,R);
	if(R>mid) ans+=answer(u<<1|1,mid+1,r,L,R);
	return ans%mod;
}
struct node{
	int x,v,id;
	bool operator <(const node a)const{return x<a.x;}
}p[N];
bool cmp(node a,node b){return a.v<b.v;}
struct ques{
	int l,r;
	bool operator <(const ques a)const{return r==a.r?l<a.l:r<a.r;}
}q[N];
int l[N],r[N],f[N];
int main()
{
	int n;
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d%d",&p[i].x,&p[i].v);
	
	sort(p+1,p+n+1,cmp);
	for(int i=1;i<=n;i++)p[i].id=i;
	sort(p+1,p+n+1);
	int res=n+1;
	for(int i=n;i;i--)
	{
		res=min(res,p[i].id);
		q[p[i].id].l=res;
	}
	res=0;
	for(int i=1;i<=n;i++)
	{
		res=max(res,p[i].id);
		q[p[i].id].r=res;
	}
	sort(q+1,q+n+1);
	ll ans=0;
	for(int i=1;i<=n;i++)
	{
		int p=q[i].l==1;
		(p+=answer(1,1,n,max(q[i].l-1,1),q[i].r))%=mod;
		insert(1,1,n,q[i].r,p);
		if(q[i].r==n) (ans+=p)%=mod;
	}
	printf("%lld",ans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:40:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:41:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  for(int i=1;i<=n;i++) scanf("%d%d",&p[i].x,&p[i].v);
                                                     ^

Judge Result