视频链接

Codeforces Round 908 (Div. 2)视频详解

A题代码

#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 fa = false;bool fb = false;for(int y = 1; y <= n; y ++){for(int x = 1; x <= n; x ++){int ca = 0, cb = 0, cat = 0, cbt = 0;for(int i = 0; i < n; i ++){if(s[i] == 'A')ca ++;elsecb ++;if(ca == x){ca = 0, cb = 0;cat ++;}if(cb == x){ca = 0, cb = 0;cbt ++;}if(cat == y){if(i < n - 1)break;fa = true;}if(cbt == y){if(i < n - 1)break;fb = true;}}}}if(fa && !fb){cout << "A" << endl;}else if(fb && !fa){cout << "B" << endl;}	else{cout << "?" << endl;}
}void solve_1()
{int n;cin >> n;string s;cin >> s;cout << s.back() << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve_1();
}

B题代码

#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;vector<int>a(n);map<int,int>st;for(int i = 0; i < n; i ++){cin >> a[i];st[a[i]] ++;}int cnt = 0;for(auto [a, b]: st)if(b >= 2)cnt ++;if(cnt < 2){cout << -1 << endl;return;}vector<int>b(n);int x = 1;for(int i = 0; i < n; i ++){if(!b[i] && st[a[i]] > 1){int col = 0;for(int j = i; j < n; j ++){if(a[j] == a[i]){b[j] = (col) % 2 + x;col ++;}}x ++;}if(x == 3)break;}for(int i = 0; i < n; i ++){if(!b[i])b[i] = 1;}for(int i = 0; i < n; i ++){cout << b[i] << " ";}cout << endl;
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve();
}

C题代码

#include <bits/stdc++.h>using namespace std;void solve() 
{int n, k;cin >> n >> k;vector<int> a(n + 1);for (int i = 1; i <= n; i++) {cin >> a[i];}k = min(k, n);int last = n;for (int i = 0; i < k; i++) {if (a[last] > n) {cout << "No\n";return;}last -= a[last];if(last <= 0)last += n;}cout << "Yes\n";
}signed main() {ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;cin >> t;while (t--) {solve();}
}

D题代码

#include<bits/stdc++.h>
#define endl '\n'
#define deb(x) cout << #x << " = " << x << '\n';
#define INF 0x3f3f3f3f
using namespace std;bool cmp(int x, int y)
{return x > y;
}
void solve()
{int n, m;cin >> n >> m;vector<int>a(n),b(m);for(int i = 0; i < n; i ++)cin >> a[i];for(int i = 0; i < m; i ++)cin >> b[i];sort(b.begin(), b.end(), cmp);int j = 0;for(int i = 0; i < n; i ++){while(j < m && b[j] >= a[i]){cout << b[j] << " ";j ++;}cout << a[i] << " ";}while(j < m)cout << b[j ++] << " ";cout << endl; 
}signed main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);int t;//t = 1;cin >> t;while(t--)solve();
}