Educational Codeforces Round 93 (Rated for Div. 2)

Problems

#	Name
A	Bad Trianglestandard input/output1 s, 256 MB		x13120
B	Substring Removal Gamestandard input/output2 s, 256 MB		x12487
C	Good Subarraysstandard input/output2 s, 256 MB		x3758
D	Colored Rectanglesstandard input/output2 s, 256 MB		x2467
E	Two Types of Spellsstandard input/output3.5 s, 256 MB		x449
F	Controversial Roundsstandard input/output2 s, 256 MB		x139
G	Running Competitionstandard input/output2 s, 512 MB		x68

Solution

A

#pragma GCC optimize(2)
#include<set>
#include<map>
#include<ctime>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define rint register int
typedef long long LL;
typedef unsigned long long ULL;
using namespace std;
const int N=5e4+5;
int T,n;
int a[N];
int main()
{
//	freopen("1.in","r",stdin);
	int i;
	scanf("%d",&T);
	while(T--) {
		scanf("%d",&n);
		for(i=1;i<=n;i++)
			scanf("%d",&a[i]);
		if(a[1]+a[2]<=a[n]) 
			printf("1 2 %d
",n);
		else printf("-1
");
	}
	return 0;
}

B

#pragma GCC optimize(2)
#include<set>
#include<map>
#include<ctime>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define rint register int
typedef long long LL;
typedef unsigned long long ULL;
using namespace std;
const int N=256;
int T,n;
char a[N];
vector<int> v;
int main()
{
//	freopen("1.in","r",stdin);
	int i;
	scanf("%d",&T);
	while(T--) {
		scanf("%s",a+1);
		n=strlen(a+1);
		v.clear();
		int cnt=0;
		for(i=1;i<=n;i++) {
			if(a[i]=='1') cnt++;
			else {
				if(cnt>0) v.push_back(cnt);	
				cnt=0;	
			}
		}
		if(cnt>0) v.push_back(cnt);
		sort(v.begin(),v.end(),greater<int>());
		int ans=0;
		for(i=0;i<(int)v.size();i+=2) 
			ans+=v[i];
		printf("%d
",ans);
	}
	return 0;
}

C

//#pragma GCC optimize(2)
#include<set>
#include<map>
#include<ctime>
#include<queue>
#include<stack>
#include<vector>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<iostream>
#include<algorithm>
#define rint register int
typedef long long LL;
typedef unsigned long long ULL;
using namespace std;
const int N=1e5+5;
int T,n;
char c[N];
int a[N],p[N];
LL f[N];
map<int,int> M;
void calc()
{
	int cha=0;
	M.clear();
	for(int i=1;i<=n;i++) {
		if(a[i]==0) p[i]=i;
		else if(M.count(-a[i]-cha)) 
			p[i]=M[-a[i]-cha];
		cha+=a[i];
		M[a[i]-cha]=i;
	}
	return;
}
int main()
{
//	freopen("1.in","r",stdin);
	int i;
	scanf("%d",&T);
	while(T--) {
		scanf("%d",&n);
		scanf("%s",c+1);
		for(i=1;i<=n;i++) 
			a[i]=(c[i]-'0')-1;
		
		memset(p,0,sizeof p);
		memset(f,0,sizeof f);
		calc();
		for(i=1;i<=n;i++) {
			if(p[i]!=0)
				f[i]=f[p[i]-1]+1;
		}
		LL ans=0;
		for(i=1;i<=n;i++) ans+=f[i];
		cout<<ans<<endl;
	}
	return 0;
}