codeforce #628 div2

A. EhAb AnD gCd

Code

#include <bits/stdc++.h>
#define ll long long
#define mem(a,v) memset(a,v,sizeof (a))
using namespace std;
const int N=2010,INF=0x3f3f3f3f;
void solve(){
	int x;
	cin>>x;
	cout<<"1"<<' '<<x-1<<endl;
}
int main(){
	int t;
	cin>>t;
	while(t--){
		solve();
	}
}

B. CopyCopyCopyCopyCopy

Code

#include<bits/stdc++.h>
using namespace std;
const int N=1e5+10;
int n;
void solve(){
	scanf("%d",&n);
	vector<int>a(n);
	for(int i=0;i<n;i++){
		scanf("%d",&a[i]);
	}
	sort(a.begin(),a.end());
	a.erase(unique(a.begin(),a.end()),a.end());
	cout<<a.size()<<endl;
}
int main(){
	int t;
	scanf("%d",&t);
	while(t--){
		solve();
	}

}

C. Ehab and Path-etic MEXs

Code

#include <bits/stdc++.h>
#define pii pair<int,int>
#define fi first
#define se second
#define pb push_back
using namespace std;
const int N=1e5+10;
vector<int>v[N];
int ans[N];
int main(){
	int n;
	scanf("%d",&n);
	for(int i=1;i<n;i++){
		int a,b;
		scanf("%d%d",&a,&b);
		v[a].pb(i);
		v[b].pb(i);
		ans[i]=-1;
	}
	pii maxv{0,0};
	for(int i=1;i<=n;i++){
		maxv=max(maxv,{v[i].size(),i});
	}
	int now=0;
	for (int i:v[maxv.second])
		ans[i]=now++;
	for(int i=1;i<n;i++){
		if(ans[i]==-1)
			ans[i]=now++;
		printf("%d\n",ans[i]);
	}
}

D. Ehab the Xorcist

#include <bits/stdc++.h>
#define pii pair<int,int>
#define fi first
#define se second
#define pb push_back
#define ll unsigned long long
using namespace std;

int main(){
	ll u,v;
	scanf("%lld%lld",&u,&v);
	if(u>v || (v-u)%2){
		puts("-1");
		return 0;
	}
	if(u==v && v==0){
		puts("0");
		return 0;
	}
	if(u==v && v!=0){
		printf("1\n%lld",u);
		return 0;
	}
	ll d=(v-u)/2;
	if(u&d){
		printf("3\n%lld %lld %lld",u,d,d);
	}
	else
		printf("2\n%lld %lld",u+d,d);
}