#include <bits/stdc++.h>
#define ff first
#define ss second
#define int long long
#define pii pair<int, int>
#define ff first
#define ss second
using namespace std;
const int inf = 1e17;
const int mod = 998244353;
void solve()
{
int n,m;
cin >> n >> m;
vector<pii> v(n);
for (int i = 0; i< n; i++)
{
cin >> v[i].ff >> v[i].ss;
while(v[i].ff>v[i].ss)
v[i].ss+=m;
}
sort(v.begin(),v.end());
{
vector<bool> del(n);
int maxi = 0;
for (int i = 0; i < n;i ++)
{
if (v[i].ss <= maxi)
del[i] = 1;
maxi = max(maxi,v[i].ss);
}
vector<pii> neu;
for (int i = 0; i < n; i++)
if (!del[i])
neu.push_back(v[i]);
n = neu.size();
v = neu;
}
for (int i = 0; i< n;i++)
v[i].ss%=m;
{
int bigie = 0;
for (int i = 0;i < n; i++)
if (v[i].ff > v[i].ss)
bigie=max(v[i].ss,bigie);
vector<bool> del(n);
for (int i = 0; i < n;i ++)
if (v[i].ff < v[i].ss && v[i].ss <= bigie)
del[i] = 1;
vector<pii> neu;
for (int i = 0; i < n; i++)
if (!del[i])
neu.push_back(v[i]);
n = neu.size();
v = neu;
}
int prev = v[0].ss;
int used = 1;
/* if (v[0].ff != 0)
{
cout << -1 << '\n';
return;
}*/
for (int i = 1; i < n; i++)
{
if (v[i].ff > prev)
{
used++;
prev = v[i-1].ss;
if (v[i].ff > prev)
{
cout << -1 << '\n';
return;
}
}
if (prev != 0 && v[i].ss == 0)
{
used++;
break;
}
}
cout << used << '\n';
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
solve();
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
352 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
352 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
352 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
344 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
1 ms |
352 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |