蒟蒻请问可不可以不用单调栈 AC,求苣佬调。
做法即对于每个点往后枚举直到最后(或极值),记录最后有效点,下次由此点开始枚举。
Code:
#pragma gcc optimize(2)
#include <iostream>
#include <algorithm>
#include <stack>
#define maxn 300010
#define inf 2147483647
using namespace std;
int n,i,ans,maxx,tmp,id;
long long a[maxn],mx;
inline int read(){
int x=0,f; char ch=0;
while(!isdigit(ch)) f=(ch=='-'?-1:1),ch=getchar();
while(isdigit(ch)) x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
return x*f;
}
inline void print(int x){
if(x<0) x=-x,putchar('-');
if(x>9) print(x/10);
putchar(x%10+48);
}
inline void write(int x){print(x);putchar('\n');}
signed main(){
n=read();
for(i=1;i<=n;i++){
a[i]=read();
if(a[i]>=mx)mx=a[i],id=i;
}
i=1,tmp=1;
while(i<=n&&tmp<=n){
i=tmp;
maxx=a[i];
ans++;
tmp++;
for(int j=i+1;j<=n;j++){
if(a[j]<a[i])break;
if(a[j]>=maxx){
maxx=a[j];
tmp=j+1;
}
if(j==id)break;
}
}
write(ans);
return 0;
}