Submission #1082523

#	Time	Username	Problem	Language	Result	Execution time	Memory
1082523		cpptowin	Lightning Rod (NOI18_lightningrod)	C++17	100 / 100	1321 ms	262144 KiB

Main

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define bitcount(x) __builtin_popcountll(x)
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define ss(x) (int)x.size()
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
    x += k;
    x %= mod;
    if(x < 0) x += mod;
}
void del(int &x, int k)
{
    x -= k;
    x %= mod;
    if(x < 0) x += mod;
}
int n,p[10000009],s[10000009];
pii a[10000009];
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n;
    p[0] = s[n + 1] = -INT_MIN;
    fo(i,1,n) 
    {
        cin >> a[i].fi >> a[i].se;
        p[i] = max(p[i - 1],a[i].se + a[i].fi);
    }
    fod(i,n,1) s[i] = max(s[i + 1],a[i].se - a[i].fi);
    int ans = 0;
    fo(i,1,n) 
    {
        bool ok = 1;
        if(i > 1 and a[i].se + a[i].fi <= p[i - 1]) ok = 0;
        if(i < n and a[i].se - a[i].fi <= s[i + 1]) ok = 0;
        ans += ok;
    }
    cout << ans;
}

Compilation message (stderr)

lightningrod.cpp:56:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   56 | main()
      | ^~~~
lightningrod.cpp: In function 'int main()':
lightningrod.cpp:67:23: warning: integer overflow in expression of type 'int' results in '-2147483648' [-Woverflow]
   67 |     p[0] = s[n + 1] = -INT_MIN;
      |                       ^
lightningrod.cpp:61:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   61 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
lightningrod.cpp:62:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   62 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 21 / 21
• Subtask 5: 26 / 26
• Subtask 6: 10 / 10
• Subtask 7: 20 / 20