#include <bits/stdc++.h>
using namespace std;
#define pii pair<int,int>
#define fi first
#define se second
const int N = 1e6 + 5;
int par[N],sz[N],h[N],f[N];
pii a[N];
void make_set(int v) {
par[v] = v;
sz[v] = 1;
}
int find_set(int v) {
if (v == par[v]) return v;
int p = find_set(par[v]);
par[v] = p;
return p;
}
void union_sets(int a,int b) {
a = find_set(a),b = find_set(b);
if (a == b) return;
if (sz[a] < sz[b]) swap(a,b);
sz[a] += sz[b];
par[b] = a;
}
int gw(int N,int *H) {
int n = N;
for (int i = 1; i <= n; i++) {
a[i].fi = H[i - 1];
a[i].se = i;
}
sort(a + 1,a + n + 1,greater<pii>());
for (int i = 1; i <= n; i++) make_set(i);
int ans = 0,cnt = 0;
for (int i = 1; i <= n; i++) {
cnt++;
if (i > 1 && f[a[i].se - 1]) {
union_sets(a[i].se - 1,a[i].se);
cnt--;
}
if (i < n && f[a[i].se + 1]) {
union_sets(a[i].se + 1,a[i].se);
cnt--;
}
f[a[i].se] = 1;
ans = max(ans,cnt);
}
return ans;
}
Compilation message
/usr/bin/ld: /usr/lib/gcc/x86_64-linux-gnu/10/../../../x86_64-linux-gnu/crt1.o: in function `_start':
(.text+0x24): undefined reference to `main'
collect2: error: ld returned 1 exit status
