Codeforces Round 956 (Div. 2)

A. Array Divisibility

Array Divisibility
直接输出1到n

#include <bits/stdc++.h>
using namespace std;

void solve() {
    int n;
    cin >> n;

    for (int i = 1; i <= n; i++) {
        cout << i << (i == n ? '\n' : ' ');
    }
}

int main(void)
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t;
    cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}

B. Corner Twist

Corner Twist
每一次都使用2*2的方块进行操作，判断将前(n-1)*(m-1)方块复原后是否相等就可以了

#include <bits/stdc++.h>
using namespace std;

void solve() {
    int n, m;
    cin >> n >> m;

    vector<string> s1(n);
    for (int i = 0; i < n; i++) {
        cin >> s1[i];
    }

	vector<string> s2(n);
    for (int i = 0; i < n; i++) {
        cin >> s2[i];
    }

    vector a(n, vector<int>(m));
    vector b(n, vector<int>(m));
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            a[i][j] = s1[i][j] - '0';
            b[i][j] = s2[i][j] - '0';
        }
    }

    for (int i = 0; i < n - 1; i++) {
        for (int j = 0; j < m - 1; j++) {
            while (a[i][j] != b[i][j]) {
                a[i][j] = (a[i][j] + 1) % 3;
                a[i][j + 1] = (a[i][j + 1] + 2) % 3;
                a[i + 1][j] = (a[i + 1][j] + 2) % 3;
                a[i + 1][j + 1] = (a[i + 1][j + 1] + 1) % 3;
            }
        }
    }

    int ans = 1;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++) {
            if (a[i][j] != b[i][j]) {
                ans = 0;
            }
        }
    }

    if (ans) {
        cout << "YES\n";
    } else {
        cout << "NO\n";
    }
}

int main(void)
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t;
    cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}

C. Have Your Cake and Eat It Too

Have Your Cake and Eat It Too
暴力枚举六种吃蛋糕的顺序即可，注意向上取整，代码写的非常丑陋

#include <bits/stdc++.h>
using namespace std;

void work(int n, long long sum, vector<int> &l, vector<int> &r, vector<long long> &a, vector<long long> &b, vector<long long> &c) {
    int ll = 0, rr = 1;
    while (rr <= n && a[rr] - a[ll] < sum) {
        rr++;
    }
    if (rr <= n) {
        l.push_back(ll + 1);
        r.push_back(rr);
    }

    ll = rr;
    rr = ll + 1;
    while (rr <= n && b[rr] - b[ll] < sum) {
        rr++;
    }
    if (rr <= n) {
        l.push_back(ll + 1);
        r.push_back(rr);
    }

    ll = rr;
    rr = n;
    if (c[rr] - c[ll] >= sum) {
        l.push_back(ll + 1);
        r.push_back(rr);
    }
}

void solve() {
    int n;
    cin >> n;

    vector<long long> a(n + 1), b(n + 1), c(n + 1);
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
    }
    for (int i = 1; i <= n; i++) {
        cin >> b[i];
    }
    for (int i = 1; i <= n; i++) {
        cin >> c[i];
    }

    long long sum = 0;
    for (int i = 1; i <= n; i++) {
        sum += a[i];
    }
    sum = (sum + 2) / 3;

    for (int i = 0; i < n; i++) {
        a[i + 1] += a[i];
        b[i + 1] += b[i];
        c[i + 1] += c[i];
    }

    vector<int> l, r;

    work(n, sum, l, r, a, b, c);
    if (l.size() == 3) {
        cout << l[0] << ' ' << r[0] << ' ';
        cout << l[1] << ' ' << r[1] << ' ';
        cout << l[2] << ' ' << r[2] << '\n';
        return;
    }

    l.clear(); r.clear();
    work(n, sum, l, r, a, c, b);
    if (l.size() == 3) {
        cout << l[0] << ' ' << r[0] << ' ';
        cout << l[2] << ' ' << r[2] << ' ';
        cout << l[1] << ' ' << r[1] << '\n';
        return;
    }

    l.clear(); r.clear();
    work(n, sum, l, r, b, a, c);
    if (l.size() == 3) {
        cout << l[1] << ' ' << r[1] << ' ';
        cout << l[0] << ' ' << r[0] << ' ';
        cout << l[2] << ' ' << r[2] << '\n';
        return;
    }

    l.clear(); r.clear();
    work(n, sum, l, r, b, c, a);
    if (l.size() == 3) {
        cout << l[2] << ' ' << r[2] << ' ';
        cout << l[0] << ' ' << r[0] << ' ';
        cout << l[1] << ' ' << r[1] << '\n';
        return;
    }

    l.clear(); r.clear();
    work(n, sum, l, r, c, b, a);
    if (l.size() == 3) {
        cout << l[2] << ' ' << r[2] << ' ';
        cout << l[1] << ' ' << r[1] << ' ';
        cout << l[0] << ' ' << r[0] << '\n';
        return;
    }

    l.clear(); r.clear();
    work(n, sum, l, r, c, a, b);
    if (l.size() == 3) {
        cout << l[1] << ' ' << r[1] << ' ';
        cout << l[2] << ' ' << r[2] << ' ';
        cout << l[0] << ' ' << r[0] << '\n';
        return;
    }

    cout << -1 << endl;
}

int main(void)
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t;
    cin >> t;
    while (t--) {
        solve();
    }

    return 0;
}