#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "debug.h"
#elif
#define debug(...) 42
#endif
#define in ({long long x = 0; int c = getchar(), n = 0; for(; !isdigit(c); c = getchar()) n = (c == '-'); for(; isdigit(c); c = getchar()) x = x * 10 + c - '0'; n ? -x : x;})
const int N = 200010;
int n, m;
long long totalWeight[N], weight[N];
struct Edge {
int u, v;
} edges[N];
int id[N];
set<int> able[N];
int root(int x) {
return !id[x] ? x : id[x] = root(id[x]);
}
int32_t main() {
cin.tie(0)->sync_with_stdio(0);
cin >> n >> m;
for (int i = 1; i <= n; ++i) {
cin >> weight[i];
totalWeight[i] = weight[i];
able[i].insert(i);
}
for (int i = 1; i <= m; ++i) {
int u, v; cin >> u >> v;
if (weight[u] > weight[v]) swap(u, v);
edges[i] = { u, v };
}
sort(edges + 1, edges + m + 1, [](Edge x, Edge y) {
return tie(weight[x.u], weight[x.v]) < tie(weight[y.u], weight[y.v]);
});
for (int i = 1; i <= m; ++i) {
auto [u, v] = edges[i];
auto [x, y] = make_pair(root(u), root(v));
if (x == y) continue;
if (able[x].size() < able[y].size()) {
swap(x, y);
swap(u, v);
}
bool leftAble = false;
bool rightAble = false;
if (totalWeight[x] >= totalWeight[y]) leftAble = true;
if (totalWeight[y] >= totalWeight[x]) rightAble = true;
if (totalWeight[x] >= weight[v] && able[y].count(v)) leftAble = true;
if (totalWeight[y] >= weight[u] && able[x].count(u)) rightAble = true;
if (leftAble && rightAble) {
able[x].insert(able[y].begin(), able[y].end());
} else if (leftAble) {
} else {
swap(able[x], able[y]);
}
id[y] = x;
totalWeight[x] += totalWeight[y];
}
int root = 1;
while (id[root]) root += 1;
for (int i = 1; i <= n; ++i) {
cout << able[root].count(i);
}
cout << '\n';
}
Compilation message
island.cpp:7:6: error: #elif with no expression
7 | #elif
| ^
