#include<bits/stdc++.h>
#define endl '\n'
using namespace std;
void speed()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
}
long long int n,a[200005],b[200005];
void fin(int i,long long int st)
{
long long int ost=st;
//cout<<endl<<i<<endl;
for(int j=i-1;j>=0;j--)
{
//cout<<j<<" ";
if(j==0)j=n;
st*=2;
if(st>=2000000000)
{
cout<<"No"<<endl;
exit(0);
}
if(a[j]-b[j]>0)
{
int g=min(a[j]-b[j],st);
st-=g;
a[j]-=g;
a[i]+=ost;
if(st==0)return;
}
}
}
void read()
{
cin>>n;
int brr=0,brr1=0;
for(int i=1;i<=n;i++)
{
cin>>a[i]>>b[i];
if(b[i]==0)brr++;
brr1+=a[i];
}
if(brr==0)
{
if(brr1)cout<<"No"<<endl;
else cout<<"Yes"<<endl;
return;
}
int pren=0;
for(int i=1;i<=n;i++)
{
a[i]+=pren;
if(a[i]>=b[i])
{
if((a[i]-b[i])%2==0)pren=(a[i]-b[i])/2;
else
{
fin(i,1);
pren=(a[i]-b[i])/2;
}
}
else fin(i,b[i]-a[i]);
//cout<<i<<" "<<a[5]<<" "<<pren<<" "<<a[3]<<endl;
}
cout<<"Yes"<<endl;
}
int main()
{
speed();
read();
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
344 KB |
Output is correct |
2 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
3 |
Halted |
0 ms |
0 KB |
- |