2024-07-10-ABC360

A - Insert

#include <bits/stdc++.h>
using namespace std;
int main() {
    int n, k, x;
    cin >> n >> k >> x;
    vector<int> a(n);
    for (auto& i : a)
        cin >> i;
    a.insert(a.begin() + k, x);
    for (auto i : a)
        cout << i << ' ';
    cout << '\n';
    return 0;
}
 

B - Intersection of Cuboids

#include <bits/stdc++.h>
using namespace std;
using LL = long long;
 
int main(void) {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
 
    int a, b, c, d, e, f;
    int g, h, i, j, k, l;
 
    cin >> a >> b >> c >> d >> e >> f;
    cin >> g >> h >> i >> j >> k >> l;
 
    auto overlap = [](int l1, int r1, int l2, int r2) {
        return max(l1, l2) < min(r1, r2);
    };
 
    bool x = overlap(a, d, g, j);
    bool y = overlap(b, e, h, k);
    bool z = overlap(c, f, i, l);
 
    if (x && y && z) {
        cout << "Yes" << endl;
    } else {
        cout << "No" << endl;
    }
 
    return 0;
}
 

C - Make Them Narrow

#include <bits/stdc++.h>
using namespace std;
int main() {
	int n, k;
	cin >> n >> k;
	vector<int> a(n);
	for (auto& x : a)
		cin >> x;
	sort(a.begin(), a.end());
	int ans = 1e9 + 7;
	for (int i = 0; i <= k; i++) {
		ans = min(ans, a[n - (k - i) - 1] - a[i]);
	}
	cout << ans << '\n';

	return 0;
}

D - Go Stone Puzzle

BFS

#include <bits/stdc++.h>
using namespace std;
int main() {
	int n;
	string s, t;
	cin >> n >> s >> t;
	vector<int> st(n + 2, 2), ed(n + 2, 2);
	for (int i = 0; i < n; i++) {
		st[i] = s[i] == 'B';
		ed[i] = t[i] == 'B';
	}
	map<vector<int>, int> cnt;
	queue<vector<int>> q;
	q.push(st);
	cnt[st] = 0;
	while (!q.empty()) {
		auto u = q.front();
		q.pop();
		int d = cnt[u];
		if (u == ed) {
			break;
		}
		int empty = find(u.begin(), u.end(), 2) - u.begin();
		for (int i = 0; i < n + 1; ++i) {
			auto v = u;
			if (v[i] != 2 && v[i + 1] != 2) {
				swap(v[i], v[empty]);
				swap(v[i + 1], v[empty + 1]);
				if (!cnt.count(v)) {
					cnt[v] = d + 1;
					q.push(v);
				}
			}
		}
	}
	if (!cnt.count(ed)) {
		cnt[ed] = -1;
	}
	cout << cnt[ed] << '\n';
	return 0;
}

E - Tree and Hamilton Path 2

#include <bits/stdc++.h>
#define LL long long
using namespace std;
vector<array<int, 2>> edge[200005];
vector<LL> dis;
void dfs(int u, int fa)
{
	for (auto [v, w] : edge[u]) {
		if (v == fa)
			continue;
		dis[v] = dis[u] + w;
		dfs(v, u);
	}
}
int main() {
	int n;
	cin >> n;
	dis.resize(n);
	LL sum = 0;
	for (int i = 0; i < n - 1; ++i) {
		int u, v, w;
		cin >> u >> v >> w;
		--u, --v;
		edge[u].push_back({v, w});
		edge[v].push_back({u, w});
		sum += w;
	}
	dfs(0, 0);
	int l = max_element(dis.begin(), dis.end()) - dis.begin();
	dis.assign(n, 0);
	dfs(l, l);
	LL max_dis = *max_element(dis.begin(), dis.end());
	cout << sum * 2 - max_dis << endl;
	return 0;
}

F - x = a^b

#include<bits/stdc++.h>

using namespace std;

long long safe_pow(long long a,long long b){
  long long res=1;
  for(long long i=0;i<b;i++){
    double dres=res;
    dres*=a;
    if(dres>2e18){return 2e18;}
    res*=a;
  }
  return res;
}

long long sqrt_floor(long long x){
  long long l=0,r=2e9;
  while(l<=r){
    long long t=(l+r)/2;
    if(t*t>x){r=t-1;}
    else{l=t+1;}
  }
  return r;
}

int main(){
  long long n;
  cin >> n;
  set<long long> st;
  for(long long b=3;b<60;b++){
    for(long long a=2;;a++){
      long long x=safe_pow(a,b);
      if(x>n){break;}
      long long s=sqrt_floor(x);
      if(s*s!=x){st.insert(x);}
    }
  }
  long long res=st.size();
  res+=sqrt_floor(n);
  cout << res << "\n";
  return 0;
}