Submission #1269830

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Source Code Expand

#include<cstring>
#include<cstdlib>
#include<cstdio>
#include<cmath>
#include<iostream>
#define N 210000
using namespace std;
int a[N],p[N],f[N],t[N],n;
bool cal(int i,int j,int k)
{
	return (p[i]<p[j])&&(p[j]<p[k]);
}
bool check(int i,int j,int k)
{
	return cal(i,j,k)|cal(j,k,i)|cal(k,i,j);
}
int main()
{
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d",&a[i]),p[a[i]]=i;
	for(int i=n-1;i>=1;i--)
		if(t[i+1]==0)
		{
			if(p[i]>p[i+1]) t[i]=1,f[i]=i+1;
		}
		else
		{
			if(check(i,i+1,f[i+1])) t[i]=t[i+1],f[i]=f[i+1];
			else t[i]=t[i+1]+1,f[i]=i+1;
		}
	printf("%d\n",t[1]);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:19:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:20:51: 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",&a[i]),p[a[i]]=i;
                                                   ^

Judge Result