cf12D. Ball
链接
点击跳转
题解
按第一关键字排序，然后倒着扫，维护线段树，下标为第二关键字，值为第三关键字
代码
#include
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
ll read(ll x=0)
{
ll c, f(1);
for(c=getchar();!isdigit(c);c=getchar())if(c=='-')f=-f;
for(;isdigit(c);c=getchar())x=x*10+c-0x30;
return f*x;
}
struct SegmentTree
{
#define inf 0x3f3f3f3f
int mn[maxn<<2], mx[maxn<<2], sum[maxn<<2], add[maxn<<2], set[maxn<<2], L[maxn<<2], R[maxn<<2];
void maketag_set(int o, int v)
{
add[o]=0;
set[o]=v;
mx[o]=mn[o]=v;
sum[o]=(R[o]-L[o]+1)*v;
}
void maketag_add(int o, int v)
{
add[o]+=v;
mx[o]+=v, mn[o]+=v;
sum[o]+=(R[o]-L[o]+1)*v;
}
void pushdown(int o)
{
if(L[o]==R[o])return;
if(~set[o])
{
maketag_set(o<<1,set[o]);
maketag_set(o<<1|1,set[o]);
set[o]=-1;
}
if(add[o])
{
maketag_add(o<<1,add[o]);
maketag_add(o<<1|1,add[o]);
add[o]=0;
}
}
void pushup(int o)
{
mx[o]=max(mx[o<<1],mx[o<<1|1]);
mn[o]=min(mn[o<<1],mn[o<<1|1]);
sum[o]=sum[o<<1]+sum[o<<1|1];
}
void build(int o, int l, int r)
{
int mid(l+r>>1);
L[o]=l, R[o]=r;
add[o]=0;
set[o]=-1;
if(l==r)
{
mn[o]=mx[o]=sum[o]=0;
return;
}
build(o<<1,l,mid);
build(o<<1|1,mid+1,r);
pushup(o);
}
void segset(int o, int l, int r, int v)
{
int mid(L[o]+R[o]>>1);
if(l<=L[o] and r>=R[o]){maketag_set(o,v);return;}
pushdown(o);
if(l<=mid)segset(o<<1,l,r,v);
if(r>mid)segset(o<<1|1,l,r,v);
pushup(o);
}
void segadd(int o, int l, int r, int v)
{
int mid(L[o]+R[o]>>1);
if(l<=L[o] and r>=R[o]){maketag_add(o,v);return;}
pushdown(o);
if(l<=mid)segadd(o<<1,l,r,v);
if(r>mid)segadd(o<<1|1,l,r,v);
pushup(o);
}
int segsum(int o, int l, int r)
{
pushdown(o);
int mid(L[o]+R[o]>>1), ans(0);
if(l<=L[o] and r>=R[o])return sum[o];
if(l<=mid)ans+=segsum(o<<1,l,r);
if(r>mid)ans+=segsum(o<<1|1,l,r);
return ans;
}
int segmin(int o, int l, int r)
{
int mid(L[o]+R[o]>>1), ans(inf);
if(l<=L[o] and r>=R[o])return mn[o];
pushdown(o);
if(l<=mid)ans=min(ans,segmin(o<<1,l,r));
if(r>mid)ans=min(ans,segmin(o<<1|1,l,r));
return ans;
}
int segmax(int o, int l, int r)
{
int mid(L[o]+R[o]>>1), ans(-inf);
if(l<=L[o] and r>=R[o])return mx[o];
pushdown(o);
if(l<=mid)ans=max(ans,segmax(o<<1,l,r));
if(r>mid)ans=max(ans,segmax(o<<1|1,l,r));
return ans;
}
#undef inf
}segtree;
struct Lisan
{
int tmp[maxn], tot;
void clear(){tot=0;}
void insert(int x){tmp[++tot]=x;}
void run()
{
sort(tmp+1,tmp+tot+1);
tot=unique(tmp+1,tmp+tot+1)-tmp-1;
}
void lisan(int *a, int len)
{
for(int i=1;i<=len;i++)a[i]=lower_bound(tmp+1,tmp+tot+1,a[i])-tmp;
}
int lisan(int x)
{
return lower_bound(tmp+1,tmp+tot+1,x)-tmp;
}
}ls;
vector<ll> a[maxn];
int main()
{
ll i, j, n, x, ans=0;
n=read();
rep(i,n)a[i].emb(read());
rep(i,n)a[i].emb(read()), ls.insert(a[i].back());
rep(i,n)a[i].emb(read());
sort(a+1,a+n+1);
ls.run();
segtree.build(1,1,ls.tot);
j=n;
for(i=n;i;i--)
{
while(a[j].at(0) > a[i].at(0))
{
auto p=ls.lisan(a[j].at(1));
ll x=segtree.segmax(1,p,p);
segtree.segset(1,p,p,max(x,a[j].at(2)));
j--;
}
if(ls.lisan(a[i].at(1))<ls.tot)
ans += segtree.segmax(1,ls.lisan(a[i].at(1))+1,ls.tot) > a[i].at(2);
}
cout<<ans;
return 0;
}