首页 > 代码库 > BZOJ3401: [Usaco2009 Mar]Look Up 仰望

BZOJ3401: [Usaco2009 Mar]Look Up 仰望

3401: [Usaco2009 Mar]Look Up 仰望

Time Limit: 3 Sec  Memory Limit: 128 MB
Submit: 87  Solved: 58
[Submit][Status]

Description

约翰的N(1≤N≤105)头奶牛站成一排,奶牛i的身高是Hi(l≤Hi≤1,000,000).现在,每只奶牛都在向左看齐.对于奶牛i,如果奶牛j满足i<j且Hi<Hj,我们可以说奶牛i可以仰望奶牛j.    求出每只奶牛离她最近的仰望对象.

Input

 
    第1行输入N,之后每行输入一个身高.

Output

 
    共N行,按顺序每行输出一只奶牛的最近仰望对象.如果没有仰望对象,输出0.

Sample Input

6
3
2
6
1
1
2

Sample Output

3
3
0
6
6
0

HINT

 

Source

Silver

题解:
裸单调栈,呵呵
代码:
 1 #include<cstdio> 2 #include<cstdlib> 3 #include<cmath> 4 #include<cstring> 5 #include<algorithm> 6 #include<iostream> 7 #include<vector> 8 #include<map> 9 #include<set>10 #include<queue>11 #include<string>12 #define inf 100000000013 #define maxn 100000+514 #define maxm 500+10015 #define eps 1e-1016 #define ll long long17 #define pa pair<int,int>18 #define for0(i,n) for(int i=0;i<=(n);i++)19 #define for1(i,n) for(int i=1;i<=(n);i++)20 #define for2(i,x,y) for(int i=(x);i<=(y);i++)21 #define for3(i,x,y) for(int i=(x);i>=(y);i--)22 #define mod 100000000723 using namespace std;24 inline int read()25 {26     int x=0,f=1;char ch=getchar();27     while(ch<0||ch>9){if(ch==-)f=-1;ch=getchar();}28     while(ch>=0&&ch<=9){x=10*x+ch-0;ch=getchar();}29     return x*f;30 }31 int n,top,a[maxn],b[maxn],sta[maxn];32 int main()33 {34     freopen("input.txt","r",stdin);35     freopen("output.txt","w",stdout);36     n=read();37     for1(i,n)a[i]=read();38     for1(i,n)39     {40         while(top&&a[i]>a[sta[top]])b[sta[top--]]=i;41         sta[++top]=i;42     }43     for1(i,n)printf("%d\n",b[i]);44     return 0;45 }
View Code

 

BZOJ3401: [Usaco2009 Mar]Look Up 仰望