//0 1 1 0 1
//0 1 0 0 1
//1 0 0 1 1
//0 1 1 0 1
#include <bits/stdc++.h>
#pragma GCC optimize("Ofast,unroll-loops")
#pragma GCC target("avx2")
using namespace std;
#define F first
#define S second
#define pb push_back
#define sze size()
#define all(x) x.begin() , x.end()
#define wall__ cout << "--------------------------------------\n";
#define kids int mid = (tl + tr) >> 1, cl = v << 1, cr = v << 1 | 1
#define file_io freopen("input.cpp", "r", stdin); freopen("output.cpp", "w", stdout);
typedef long long ll;
typedef long double dl;
typedef pair < int , int > pii;
typedef pair < int , ll > pil;
typedef pair < ll , int > pli;
typedef pair < ll , ll > pll;
typedef pair < int , pii > piii;
typedef pair < ll, pll > plll;
const ll N = 1e6 + 10;
const ll mod = 1e9 + 7;
const ll inf = 2e16;
const ll rinf = -2e16;
const ll INF = 1e9 + 10;
const ll rINF = -1e9 - 10;
const ll lg = 32;
ll a[N], b[N], n;
int mark[N];
bool be_lock (int idx) {
if (a[idx] <= b[idx] + 1ll) return true;
return false;
}
void solve () {
cin >> n;
ll s = 0;
for (int i = 0; i < n; i++) {
cin >> a[i] >> b[i];
s += a[i]; s -= b[i];
}
int lock = 0;
int i = 0;
while (s > 0 && lock < n) {
ll x = a[i] - b[i];
s -= a[i]; s -= a[(i + 1) % n];
if (x > 0) {
x /= 2ll;
a[i] -= (2ll * x);
a[(i + 1) % n] += x;
}
s += a[i];
s += a[(i + 1) % n];
int t = be_lock(i);
lock -= mark[i]; lock += t;
t = be_lock((i + 1) % n);
lock -= mark[(i + 1) % n]; lock += t;
mark[i] = t; mark[(i + 1) % n] = t;
++i; i %= n;
}
int c = 0;
for (int i = 0; i < n; i++) {
if (a[i] != b[i]) ++c;
}
if (c) cout << "No\n";
else cout << "Yes\n";
}
int main() {
ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
int t = 1;
// cin >> t;
while (t--) {solve();}
return 0;
}
/*
5
0 0
1 2
2 4
3 2
4 0
*/
//shrek will AC this;
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
1 ms |
328 KB |
Output is correct |
5 |
Correct |
1 ms |
340 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
1 ms |
328 KB |
Output is correct |
5 |
Correct |
1 ms |
340 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
1 ms |
340 KB |
Output is correct |
2 |
Correct |
0 ms |
340 KB |
Output is correct |
3 |
Correct |
1 ms |
340 KB |
Output is correct |
4 |
Correct |
1 ms |
328 KB |
Output is correct |
5 |
Correct |
1 ms |
340 KB |
Output is correct |
6 |
Correct |
1 ms |
332 KB |
Output is correct |
7 |
Incorrect |
1 ms |
340 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |