2024牛客寒假算法基础集训营1（视频讲解全部题目）

2024牛客寒假算法基础集训营1（视频讲解全部题目）

A

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
using namespace std;void solve()
{int n; cin >> n;string s; cin >> s;bool f = false, F = false;for(int i = 0; i < n; i ++){if(s[i] == 'd'){for(int j = i + 1; j < n; j ++){if(s[j] == 'f'){for(int k = j + 1; k < n; k ++){if(s[k] =='s'){f = true; }}}}}}for(int i = 0; i < n; i ++){if(s[i] == 'D'){for(int j = i + 1; j < n; j ++){if(s[j] == 'F'){for(int k = j + 1; k < n; k ++){if(s[k] =='S'){F = true; }}}}}}cout << F << " " << f << endl;	
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve();
}

B

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
#define x first
#define y second
#define int long long
using namespace std;
typedef pair<int,int> pii;
int dc[3] = {-1, 0, 1};
void solve()
{int n; cin >> n;int l = 2, r = 2;vector<pii>lp, rp;map<pii,bool>st;for(int i = 0; i < n; i ++){int r, c; cin >> r >> c;st[{c,r}] = true;if(c <= 0){lp.push_back({c, r});}else if(c > 0){rp.push_back({c, r});}}if(lp.size()){for(int i = 0; i < lp.size(); i ++){if(lp[i].first == 0 and lp[i].second == 2){if(!st[{-1, 1}]){l = min(1ll, l);}else{l = 0;}continue;}for(int j = 0; j < 3; j ++){int nc = lp[i].x + dc[j];int nr = 3 - lp[i].y;if(st[{nc, nr}]){l = 0;}else{l = min(l, 1ll);}}}}if((st[{-1, 1}] and l == 1)){st[{0, 2}] = true;}if(l == 2){st[{0, 2}] = true;}if(rp.size()){for(int i = 0; i < rp.size(); i ++){for(int j = 0; j < 3; j ++){int nc = rp[i].x + dc[j];int nr = 3 - rp[i].y;if(st[{nc, nr}]){r = 0;}else{r = min(r, 1ll);}}}}else{if(st[{0, 2}]){r = 1;}}int ans = l + r;cout << ans << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve();
}

C

#include<bits/stdc++.h>
#define endl '\n'
#define int long long
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f3f3f3f3f
using namespace std;void solve()
{int n, q, tc; cin >> n >> q >> tc;vector<int>t(n + 1);vector<int>s(n + 1);vector<int>ss(n + 1);for(int i = 1; i <= n; i ++){cin >> t[i];}sort(t.begin() + 1, t.end());for(int i = 1; i <= n; i ++){s[i] = s[i - 1] + t[i];}for(int i = 1; i <= n; i ++){ss[i] = ss[i - 1] + s[i];}while(q--){int M; cin >> M;int l = 1, r = n;while(l < r){int mid = l + r >> 1;int cnt = n - mid + 1;if(cnt * tc <= M){r = mid;}else{l = mid + 1;}}if(l == n){if(tc > M){cout << s[n] + tc << endl;continue;} }cout << s[l - 1] + tc << endl;}
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;t = 1;//cin >> t;while(t--)solve();
}

D

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
#define int long long
using namespace std;void solve()
{int n, m; cin >> n >> m;vector<int>a(n);map<int,int>cnt;set<int>ans;ans.insert(0);for(int i = 0; i < n; i ++){cin >> a[i];cnt[a[i]] += 1;}if(n >= 30){//一定要减少绝对值不等于1的数字个数。for(auto [x, y]: cnt){if(n - cnt[x] - cnt[x - 2] > 30)continue;int mul = 1;bool flag = true;for(int i = 0; i < n; i ++){mul = mul * (a[i] - (x - 1));if(abs(mul) > 1e9){flag = false;break;}}if(flag)ans.insert(mul);mul = 1, flag = true;for(int i = 0; i < n; i ++){mul = mul * (a[i] - (x + 1));if(abs(mul) > 1e9){flag = false;break;}}if(flag)ans.insert(mul);}}else{//如果n <= 30sort(a.begin(), a.end());int tmp = a[0];for(int i = 0; i < n; i ++){a[i] -= tmp;}for(int i = -1e6; i <= 1e6; i ++){int mul = 1;bool flag = true;for(int j = 0; j < n; j ++){mul = mul * (a[j] + i);if(abs(mul) > 1e9){flag = false;break;}}if(flag)ans.insert(mul);}reverse(a.begin(), a.end());tmp = a[0];for(int i = 0; i < n; i ++){a[i] -= tmp;}for(int i = -1e6; i <= 1e6; i ++){int mul = 1;bool flag = true;for(int j = 0; j < n; j ++){mul = mul * (a[j] + i);if(abs(mul) > 1e9){flag = false;break;}}if(flag)ans.insert(mul);}}while(m--){int x; cin >> x;if(ans.count(x)){cout << "Yes" << endl;}else{cout << "No" << endl;}}}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;t = 1;//cin >> t;while(t--)solve();
}

E

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
using namespace std;
typedef pair<int,int> pii;void solve()
{int n, m; cin >> n >> m;vector<int>a(n);vector<pii>b(m);for(int i = 0; i < n; i ++){cin >> a[i];}for(int i = 0; i < m; i ++){int u, v; cin >> u >> v;u --, v --;b[i] = {u, v};}int ans = 11;function<void(int)> dfs = [&](int u)->void{if(u >= m){int sc = a[0];int top = 1;for(int i = 1; i < n; i ++){if(a[i] > sc){top ++;}}ans = min(ans, top);return;}int x = b[u].first, y = b[u].second;a[x] += 3;dfs(u + 1);//回溯a[x] -= 3;a[y] += 3;dfs(u + 1);a[y] -= 3;a[x] += 1, a[y] += 1;dfs(u + 1);a[x] -= 1, a[y] -= 1;};dfs(0);cout << ans << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve();
}

F

#include<bits/stdc++.h>
#define endl '\n'
#define int long long
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
using namespace std;
const int N = 1e5 + 10;
const int mod = 1e9 + 7;int fact[N], infact[N];int qmi(int a, int b, int p){int res = 1;while(b){if(b & 1)res = res * a % p;a = a * a % p;b >>= 1;}return res;
}void init(){fact[0] = infact[0] = 1;for(int i = 1; i < N; i ++){fact[i] = fact[i - 1] * i % mod;infact[i] = infact[i - 1] * qmi(i, mod - 2, mod) % mod;}
}void solve()
{int n, m; cin >> n >> m;int res = 0;for(int i = 0; i <= m; i ++){if((m - i) % 2){res = ((res - (qmi(i, n, mod) * infact[i] % mod * infact[m - i] % mod)) % mod + mod) % mod;}else{res = (res + (qmi(i, n, mod) * infact[i] % mod * infact[m - i] % mod)) % mod;}}cout << res << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;t = 1;// cin >> t;init();while(t--)solve();
}

G

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define x first
#define y second
#define int long long
#define INF 0x3f3f3f3f
using namespace std;
typedef pair<int,int> pii;void solve()
{int n, m; cin >> n >> m;vector<pii>a(n + 1);for(int i = 1; i <= n; i ++){cin >> a[i].x >> a[i].y;}sort(a.begin(), a.end());vector<int>s(n + 1);for(int i = 1; i <= n; i ++){s[i] = s[i - 1] + a[i].y;}int ans = m;for(int i = n; i >= 1; i --){int dis = a[i].x - s[i];if(dis > m){continue;}ans = max(ans, m + s[i]);}cout << ans << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve();
}

H

#include<bits/stdc++.h>
#define endl '\n'
#define int long long
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
using namespace std;void solve()
{int n, m; cin >> n >> m;vector<int>v(n), w(n);for(int i = 0; i < n; i ++){cin >> v[i] >> w[i];}int ans = 0, pre = 0;for(int i = 31; i >= 0; i --){int x = pre;if((m >> i) & 1){x += (1 << i) - 1;pre += (1 << i);}int sum = 0;for(int j = 0; j < n; j ++){if((x | w[j]) == x){sum += v[j];}}ans = max(ans, sum);}int sum = 0;for(int j = 0; j < n; j ++){if((m | w[j]) == m){sum += v[j];}}ans = max(ans, sum);cout << ans << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve();
}

I

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
using namespace std;
uniform_int_distribution<int> u1(-99,99);//生成圆心
uniform_int_distribution<int> u2(1,100);//生成半径
default_random_engine e;void test()
{int n = 1e5;double r1 = 0;for(int i = 1; i <= n; i ++){int x = u1(e), y = u1(e);while(1){int r = u2(e);if(x + r > 100 || x - r < -100 || y + r > 100 || y - r < -100){continue;}else{r1 += (r);break;}} }double r2 = 0;for(int i = 1; i <= n; i ++){while(1){int x = u1(e), y = u1(e);int r = u2(e);if(x + r > 100 || x - r < -100 || y + r > 100 || y - r < -100){continue;}else{r2 += (r);break;}} }r1 = r1 / n;r2 = r2	/ n;cout << r1 << " " << r2 << endl;
}
void solve(){int n; cin >> n;double sum = 0;for(int i = 0; i < n; i ++){int x, y, r; cin >> x >> y >> r;sum += r; }sum /= n;if((int)sum == 17){cout << "bit-noob" << endl;}else{cout << "buaa-noob" << endl;}
}
signed main()
{e.seed(time(NULL));ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)// solve();test();
}

J

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
using namespace std;void solve()
{int n, x, y; cin >> n >> x >> y;vector<int>a(n);for(int i = 0; i < n; i ++){cin >> a[i];}auto check = [&](int dis)->bool{// cout << dis << endl;set<int>st;st.insert(x), st.insert(y);if(abs(x - y) > dis){return false;}for(int i = 0; i < a.size(); i ++){while(st.size() and abs(*st.begin() - a[i]) > dis){st.erase(st.begin());}while(st.size() and abs(*st.rbegin() - a[i]) > dis){st.erase(*st.rbegin());}if(!st.size()){return false;}st.insert(a[i]);}return true;};int l = 0, r = 1e9;while(l < r){int mid = l + r >> 1;if(check(mid)){r = mid;}else{l = mid + 1;}}cout << l << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;t = 1;// cin >> t;while(t--)solve();
}

K

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
#define int long long
using namespace std;
const int N = 1e5 + 10;
const int mod = 998244353;
int nex[N];
string choice[N];
int p[N], in[N];
bool st[N];
char t[N];
set<int> root;
int nums;int find(int x){if(x != p[x])p[x] = find(p[x]);return p[x];
}void init(int x){for(int i = 1; i <= x; i ++){p[i] = i;root.insert(i);}
}void merge(int x, int y){int px = find(x);int py = find(y);if(px != py){if(in[px]){p[px] = py;root.erase(px);}else{p[py] = px;root.erase(py);}}
}void dfs(int u, char answer){if(st[nex[u]]){if(answer == t[nex[u]]){nums ++;}return;}char nex_answer = choice[nex[u]][answer - 'A'];t[nex[u]] = answer;st[nex[u]] = true;dfs(nex[u], nex_answer);	st[nex[u]] = false;
}void solve()
{int n; cin >> n;init(n);for(int i = 1; i <= n; i ++){int x; string s;cin >> x >> s;choice[i] = s;nex[i] = x;in[x] ++;merge(x, i);}int ans = 1;for(auto x: root){for(int i = 0; i < 5; i ++){t[x] = ('A' + i);st[x] = true;dfs(x, choice[x][i]);}ans = nums * ans % mod;nums = 0;}cout << ans << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;t = 1;// cin >> t;while(t--)solve();
}

L

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
using namespace std;void solve()
{int c, d, h, w;cin >> c >> d >> h >> w;cout << 3 * w * c << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve();
}

M

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
#define int long long
using namespace std;void solve()
{int n; cin >> n;if(n % 6)cout << (n / 6) * 2 << endl;elsecout << (n / 6) << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve();
}