bzoj3401 [Usaco2009 Mar]Look Up 仰望

#include<bits/stdc++.h>
#define N 100000
using namespace std;
int n,A[N+5];
int stk[N+5],top;
int ans[N+5];
inline char nc()
{
static char buf[100000],*p1=buf,*p2=buf;
return p1==p2&&(p2=(p1=buf)+fread(buf,1,100000,stdin),p1==p2)?EOF:*p1++;
}
inline int read()
{
int x=0,b=1;
char c=nc();
for(;!(c<='9'&&c>='0');c=nc())if(c=='-')b=-1;
for(;c<='9'&&c>='0';c=nc())x=x*10+c-'0';
return x*b;
}
inline void write(int x)
{
if(x==0)putchar('0');
else
{
char buf[15];
int len=0;
if(x<0)putchar('-'),x=-x;
while(x)buf[++len]=x%10+'0',x/=10;
for(int i=len;i>=1;i--)putchar(buf[i]);
}
putchar('\n');
}
int main()
{
freopen("in.txt","r",stdin);
n=read();
for(int i=1;i<=n;i++)A[i]=read();
for(int i=n;i>=1;i--)
{
while(top&&A[stk[top]]<=A[i])top--;
ans[i]=stk[top];
stk[++top]=i;
}
for(int i=1;i<=n;i++)write(ans[i]);
return 0;
}