Submission #1269872

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Source Code Expand

#include <cstdio>
#include <iostream>
#include <algorithm>
#define N 200010

using namespace std;

int n;
int a[N],p[N],t[N],f[N];

inline bool in_cyclic(int a,int b,int c){
	return (a<b&&b<c)||(b<c&&c<a)||(c<a&&a<b);
}

int main(){
	scanf("%d",&n);
	for(int i=1;i<=n;i++) scanf("%d",&a[i]),p[a[i]]=i;
	t[n]=f[n]=0;
	for(int i=n-1;i;i--){
		if(t[i+1]==0)
			if(p[i]>p[i+1]) t[i]=1,f[i]=i+1;
			else t[i]=f[i]=0;
		else
			if(in_cyclic(p[f[i+1]],p[i],p[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:16:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
                ^
./Main.cpp:17:51: 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