Codeforces Round #644 (Div. 3)

题目传送门

还是视频题解。没什么好说的，题目感觉都比较简单。。但题量确实大。

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A. Minimal Square

/*
 * Author:  heyuhhh
 * Created Time:  2020/5/25 9:56:17
 */
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <iomanip>
#include <assert.h>
#define MP make_pair
#define fi first
#define se second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define INF 0x3f3f3f3f
#define Local
#ifdef Local
  #define dbg(args...) do { cout << #args << " -> "; err(args); } while (0)
  void err() { std::cout << std::endl; }
  template<typename T, typename...Args>
  void err(T a, Args...args) { std::cout << a << ' '; err(args...); }
  template <template<typename...> class T, typename t, typename... A> 
  void err(const T <t> &arg, const A&... args) {
  for (auto &v : arg) std::cout << v << ' '; err(args...); }
#else
  #define dbg(...)
#endif
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
//head
const int N = 1e5 + 5;
 
void run() {
    int a, b; cin >> a >> b;
    if (a > b) swap(a, b);
    a *= 2;
    int n = max(a, b);
    cout << n * n << '\n';
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cout << fixed << setprecision(20);
    int T; cin >> T; while(T--)
    run();
    return 0;
}

B. Honest Coach

/*
 * Author:  heyuhhh
 * Created Time:  2020/5/25 9:59:00
 */
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <iomanip>
#include <assert.h>
#define MP make_pair
#define fi first
#define se second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define INF 0x3f3f3f3f
#define Local
#ifdef Local
  #define dbg(args...) do { cout << #args << " -> "; err(args); } while (0)
  void err() { std::cout << std::endl; }
  template<typename T, typename...Args>
  void err(T a, Args...args) { std::cout << a << ' '; err(args...); }
  template <template<typename...> class T, typename t, typename... A> 
  void err(const T <t> &arg, const A&... args) {
  for (auto &v : arg) std::cout << v << ' '; err(args...); }
#else
  #define dbg(...)
#endif
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
//head
const int N = 1e5 + 5;
 
void run() {
    int n; cin >> n;
    vector <int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    int d = INF;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) {
            if (i != j) d = min(d, abs(a[i] - a[j]));
        }
    }
    cout << d << '\n';
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cout << fixed << setprecision(20);
    int T; cin >> T; while(T--)
    run();
    return 0;
}

C. Similar Pairs

/*
 * Author:  heyuhhh
 * Created Time:  2020/5/25 9:48:00
 */
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <iomanip>
#include <assert.h>
#define MP make_pair
#define fi first
#define se second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define INF 0x3f3f3f3f
#define Local
#ifdef Local
  #define dbg(args...) do { cout << #args << " -> "; err(args); } while (0)
  void err() { std::cout << std::endl; }
  template<typename T, typename...Args>
  void err(T a, Args...args) { std::cout << a << ' '; err(args...); }
  template <template<typename...> class T, typename t, typename... A> 
  void err(const T <t> &arg, const A&... args) {
  for (auto &v : arg) std::cout << v << ' '; err(args...); }
#else
  #define dbg(...)
#endif
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
//head
const int N = 50 + 5;
 
void run() {
    int n; cin >> n;
    vector <int> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];   
    }
    sort(all(a));
    int cnt[2] = {0, 0};
    for (auto it : a) {
        ++cnt[it % 2];
    }
    if (cnt[0] % 2 == 0) {
        cout << "YES" << '\n';
        return;
    }
    for (int i = 1; i < n; i++) {
        if (a[i] == a[i - 1] + 1) {
            cout << "YES" << '\n';
            return;
        }
    }
    cout << "NO" << '\n';
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cout << fixed << setprecision(20);
    int T; cin >> T; while(T--)
    run();
    return 0;
}

D. Buying Shovels

/*
 * Author:  heyuhhh
 * Created Time:  2020/5/25 9:42:25
 */
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <iomanip>
#include <assert.h>
#define MP make_pair
#define fi first
#define se second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define INF 0x3f3f3f3f
#define Local
#ifdef Local
  #define dbg(args...) do { cout << #args << " -> "; err(args); } while (0)
  void err() { std::cout << std::endl; }
  template<typename T, typename...Args>
  void err(T a, Args...args) { std::cout << a << ' '; err(args...); }
  template <template<typename...> class T, typename t, typename... A> 
  void err(const T <t> &arg, const A&... args) {
  for (auto &v : arg) std::cout << v << ' '; err(args...); }
#else
  #define dbg(...)
#endif
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
//head
const int N = 1e5 + 5;
 
void run() {
    int n, k; cin >> n >> k;
    vector <int> d;
    for (int i = 1; 1ll * i * i <= n; i++) {
        if (n % i == 0) {
            d.push_back(i);
            if (i != n / i) d.push_back(n / i);
        }
    }
    sort(all(d));
    int p = upper_bound(all(d), k) - d.begin() - 1;
    cout << n / d[p] << '\n';
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cout << fixed << setprecision(20);
    int T; cin >> T; while(T--)
    run();
    return 0;
}

E. Polygon

/*
 * Author:  heyuhhh
 * Created Time:  2020/5/25 9:35:58
 */
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <iomanip>
#include <assert.h>
#define MP make_pair
#define fi first
#define se second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define INF 0x3f3f3f3f
#define Local
#ifdef Local
  #define dbg(args...) do { cout << #args << " -> "; err(args); } while (0)
  void err() { std::cout << std::endl; }
  template<typename T, typename...Args>
  void err(T a, Args...args) { std::cout << a << ' '; err(args...); }
  template <template<typename...> class T, typename t, typename... A> 
  void err(const T <t> &arg, const A&... args) {
  for (auto &v : arg) std::cout << v << ' '; err(args...); }
#else
  #define dbg(...)
#endif
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
//head
const int N = 1e5 + 5;
 
void run() {
    int n; cin >> n;
    vector <string> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }
    auto ok = [&] (int i, int j) {
        return i + 1 >= n || j + 1 >= n || a[i + 1][j] == '1' || a[i][j + 1] == '1';   
    };
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < n; j++) if (a[i][j] == '1') {
            if (ok(i, j)) {}
            else {
                cout << "No" << '\n';
                return;
            }
        }
    }
    cout << "Yes" << '\n';
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cout << fixed << setprecision(20);
    int T; cin >> T; while(T--)
    run();
    return 0;
}

F. Spy-string

/*
 * Author:  heyuhhh
 * Created Time:  2020/5/24 22:33:18
 */
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <iomanip>
#include <assert.h>
#define MP make_pair
#define fi first
#define se second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define INF 0x3f3f3f3f
#define Local
#ifdef Local
  #define dbg(args...) do { cout << #args << " -> "; err(args); } while (0)
  void err() { std::cout << std::endl; }
  template<typename T, typename...Args>
  void err(T a, Args...args) { std::cout << a << ' '; err(args...); }
  template <template<typename...> class T, typename t, typename... A> 
  void err(const T <t> &arg, const A&... args) {
  for (auto &v : arg) std::cout << v << ' '; err(args...); }
#else
  #define dbg(...)
#endif
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
//head
 
void run() {
    int n, m;
    cin >> n >> m;
    vector <string> s(n);
    for (int i = 0; i < n; i++) {
        cin >> s[i];
    }
    string res = s[0];
    auto chk = [&] (int k) {
        for (int i = 0; i < n; i++) {
            vector <int> p;
            for (int j = 0; j < m; j++) {
                if (s[i][j] != res[j]) p.push_back(j);
            }
            if (sz(p) > 2) return false;
            if (sz(p) < 2) {
                if (sz(p) == 1) {
                    if (p[0] != k) k = -1;
                }
                continue;
            }
            if (p[0] == k || p[1] == k) {
                res[k] = s[i][k];
                k = -1;
            } else return false;
        }
        return true;
    };
    for (int k = 0; k < m; k++) {
        res = s[0];
        if (chk(k)) {
            cout << res << '\n';
            return;
        }
    }
    cout << -1 << '\n';
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cout << fixed << setprecision(20);
    int T; cin >> T; while(T--)
    run();
    return 0;
}

G. A/B Matrix

/*
 * Author:  heyuhhh
 * Created Time:  2020/5/24 22:24:07
 */
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <iomanip>
#include <assert.h>
#define MP make_pair
#define fi first
#define se second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define INF 0x3f3f3f3f
#define Local
#ifdef Local
  #define dbg(args...) do { cout << #args << " -> "; err(args); } while (0)
  void err() { std::cout << std::endl; }
  template<typename T, typename...Args>
  void err(T a, Args...args) { std::cout << a << ' '; err(args...); }
  template <template<typename...> class T, typename t, typename... A> 
  void err(const T <t> &arg, const A&... args) {
  for (auto &v : arg) std::cout << v << ' '; err(args...); }
#else
  #define dbg(...)
#endif
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
//head
const int N = 1e5 + 5;
 
void run() {
    int n, m, a, b; cin >> n >> m >> a >> b;
    vector <vector <int>> mat(n, vector <int> (m));
    vector <int> cols(m);
    for (int i = 0, p = 0; i < n; i++) {
        for (int j = p; j < p + a; j++) {
             mat[i][j % m] = 1;
             ++cols[j % m];
        }
        p += a;
    }
    for (int i = 0; i < m; i++) {
        if (cols[i] != b) {
            cout << "NO" << '\n';
            return;
        }
    }
    cout << "YES" << '\n';
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            cout << mat[i][j];
        }
        cout << '\n';
    }
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cout << fixed << setprecision(20);
    int T; cin >> T; while(T--)
    run();
    return 0;
}

H. Binary Median

/*
 * Author:  heyuhhh
 * Created Time:  2020/5/24 22:00:13
 */
#include <iostream>
#include <algorithm>
#include <cstring>
#include <cstdio>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <iomanip>
#include <assert.h>
#define MP make_pair
#define fi first
#define se second
#define pb push_back
#define sz(x) (int)(x).size()
#define all(x) (x).begin(), (x).end()
#define INF 0x3f3f3f3f
#define Local
#ifdef Local
  #define dbg(args...) do { cout << #args << " -> "; err(args); } while (0)
  void err() { std::cout << std::endl; }
  template<typename T, typename...Args>
  void err(T a, Args...args) { std::cout << a << ' '; err(args...); }
  template <template<typename...> class T, typename t, typename... A> 
  void err(const T <t> &arg, const A&... args) {
  for (auto &v : arg) std::cout << v << ' '; err(args...); }
#else
  #define dbg(...)
#endif
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
//head
const int N = 100 + 5, M = 65;
 
int n, m;
 
void run() {
    cin >> n >> m;
    ll k = (1ll << m);
    vector <ll> a;
    map <ll, int> mp;
    for (int i = 1; i <= n; i++) {
        string s; cin >> s;
        reverse(all(s));
        ll x = 0, pow2 = 1;
        for (int i = 0; i < s.length(); i++) {
            x += pow2 * (s[i] - '0');
            pow2 *= 2;
        }
        a.push_back(x);
    }
    sort(all(a));
    ll p = (k - 1) / 2;
    for (int i = 0; i < sz(a); i++) {
        mp[a[i]] = 1;
        --k;
        if (k % 2 == 0) {
            if (a[i] >= p) {
                --p;
                while (mp[p]) --p;
            }
        } else if(a[i] <= p) {
            ++p;
            while (mp[p]) ++p;
        }
    }
    string res = "";
    for (int i = 0; i < m; i++) {
        if (p >> i & 1) res += '1';
        else res += '0';
    }
    reverse(all(res));
    cout << res << '\n';
}
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    cout << fixed << setprecision(20);
    int T; cin >> T; while(T--)
    run();
    return 0;
}