Submission #296139

#	Time	Username	Problem	Language	Result	Execution time	Memory
296139		Pyqe	Monochrome Points (JOI20_monochrome)	C++14	100 / 100	45 ms	2880 KiB

monochrome

#include <bits/stdc++.h>

using namespace std;

long long n,ps[200069];
bitset<400069> a;

int main()
{
	long long i,z;
	string s;
	
	scanf("%lld",&n);
	z=n*(n-1)/2;
	cin>>s;
	for(i=1;i<=n*2;i++)
	{
		a[i]=s[i-1]=='W';
	}
	for(i=1;i<=n;i++)
	{
		ps[i]=ps[i-1]+((!a[i]*2-1)*(a[i]==a[n+i]));
	}
	sort(ps+1,ps+n+1);
	for(i=1;i<=n;i++)
	{
		z-=abs(ps[i]-ps[(n+1)/2]);
	}
	printf("%lld\n",z);
}

Compilation message (stderr)

monochrome.cpp: In function 'int main()':
monochrome.cpp:13:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   13 |  scanf("%lld",&n);
      |  ~~~~~^~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 21 / 21
• Subtask 3: 10 / 10
• Subtask 4: 65 / 65