Codeforces
CF Step
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Code

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

void solve() {
    int n, q;
    cin >> n >> q;
    vector<long long> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    vector<long long> global_copy_of_a = a;

    for (int zz = 0; zz < q; zz++) {
        a = global_copy_of_a;
        long long k;
        cin >> k;

        // Iterate through higher order bits to lower order.
        long long answer = 0;

        // What's the safest highest bit?
        for (int bit = 62; bit >= 0; bit--) {
            int current_and = 1;
            for (int i = 0; i < n; i++) {
                if ((1LL << bit) & a[i]) {
                    current_and &= 1;
                } else {
                    current_and &= 0;
                }
            }

            if (current_and == 1) {
                answer |= (1LL << bit);
                continue;
            }

            // Else, try to use it.
            long long need = 0;

            // Don't accumulate sum all at once to prevent overflow.
            bool effort_success = true;
            long long previous_k = k;

            auto local_copy_of_a = a;
            for (int i = 0; i < n; i++) {
                if ((1LL << bit) & a[i]) {
                    // If the bit is already set, skip it.
                } else {
                    long long copy = a[i];
                    long long cost;

                    // Borrow it if possible.
                    if (bit >= 1 && ((1LL << (bit - 1) & a[i]) != 0)) {
                        cost = 1LL << (bit - 1);

                        // Unset the lower order bit.
                        a[i] &= ~(1LL << (bit - 1));
                    } else {
                        cost = 1LL << bit;
                    }
                    if (k >= cost) {
                        k -= cost;
                    } else {
                        effort_success = false;
                        break;
                    }
                }
            }

            if (!effort_success) {
                a = local_copy_of_a;
                // Reverse all operations
                k = previous_k;

            } else {
                answer |= (1LL << bit);
            }
        }

        cout << answer << "\n";
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    solve();

    return 0;
}
#include <bits/stdc++.h>
using namespace std;

void solve() {
    int n, q;
    cin >> n >> q;
    vector<long long> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    vector<long long> global_copy_of_a = a;

    for (int zz = 0; zz < q; zz++) {
        a = global_copy_of_a;
        long long k;
        cin >> k;

        // Iterate through higher order bits to lower order.
        long long answer = 0;

        // What's the safest highest bit?
        for (int bit = 62; bit >= 0; bit--) {
            int current_and = 1;
            for (int i = 0; i < n; i++) {
                current_and &= ((1LL << bit) & a[i]) != 0;
            }

            if (current_and == 1) {
                // Clear all higher bits.
                for (int i = 0; i < n; i++) {
                    a[i] &= ~(1LL << bit);
                }
                answer |= (1LL << bit);
                continue;
            }

            // Don't accumulate sum all at once to prevent overflow.
            bool effort_success = true;
            long long previous_k = k;
            auto local_copy_of_a = a;
            for (int i = 0; i < n; i++) {
                if ((1LL << bit) & a[i]) {
                    // If the bit is already set, skip it.
                } else {
                    // You can assume that higher order bits don't exist.
                    long long cost = (1LL << bit) - a[i];
                    if (k >= cost) {
                        k -= cost;
                    } else {
                        effort_success = false;
                        break;
                    }

                    // If it is possible to turn on this bit, it means that
                    // the new number is 000 (1) 0000.
                    a[i] = (1LL << bit);
                }
            }

            if (!effort_success) {
                // Reverse all operations
                a = local_copy_of_a;
                k = previous_k;
            } else {
                answer |= (1LL << bit);
            }

            // Clear all higher bits.
            for (int i = 0; i < n; i++) {
                a[i] &= ~(1LL << bit);
            }
        }

        cout << answer << "\n";
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    solve();

    return 0;
}
#include <bits/stdc++.h>
using namespace std;

void solve() {
    int n, q;
    cin >> n >> q;
    vector<long long> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    vector<long long> global_copy_of_a = a;

    for (int zz = 0; zz < q; zz++) {
        a = global_copy_of_a;
        long long k;
        cin >> k;

        // Iterate through higher order bits to lower order.
        long long answer = 0;

        // What's the safest highest bit?
        for (int bit = 62; bit >= 0; bit--) {
            int current_and = 1;
            for (int i = 0; i < n; i++) {
                if ((1LL << bit) & a[i]) {
                    current_and &= 1;
                } else {
                    current_and &= 0;
                }
            }

            if (current_and == 1) {
                answer |= (1LL << bit);
                continue;
            }

            // Else, try to use it.
            long long need = 0;

            // Don't accumulate sum all at once to prevent overflow.
            bool effort_success = true;
            long long previous_k = k;

            auto local_copy_of_a = a;
            for (int i = 0; i < n; i++) {
                if ((1LL << bit) & a[i]) {
                    // If the bit is already set, skip it.
                } else {
                    // If it is possible to turn on this bit, it means that
                    // the new number is xyz (1) 0000. Hence, turn of all lower
                    // order bits.
                    long long relief = 0;
                    for (int lower = bit - 1; lower >= 0; lower--) {
                        if ((1LL << lower) & a[i]) {
                            // Unset the lower order bit.
                            a[i] &= ~(1LL << (lower));
                            relief += (1LL << lower);
                        }
                    }

                    long long cost = (1LL << bit) - relief;
                    if (k >= cost) {
                        k -= cost;
                    } else {
                        effort_success = false;
                        break;
                    }
                }
            }

            if (!effort_success) {
                a = local_copy_of_a;
                // Reverse all operations
                k = previous_k;

            } else {
                answer |= (1LL << bit);
            }
        }

        cout << answer << "\n";
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    solve();

    return 0;
}
#include <bits/stdc++.h>
using namespace std;

void solve() {
    int n, q;
    cin >> n >> q;
    vector<long long> a(n);
    for (int i = 0; i < n; i++) {
        cin >> a[i];
    }

    vector<long long> global_copy_of_a = a;

    for (int zz = 0; zz < q; zz++) {
        a = global_copy_of_a;
        long long k;
        cin >> k;

        // Iterate through higher order bits to lower order.
        long long answer = 0;

        // What's the safest highest bit?
        for (int bit = 62; bit >= 0; bit--) {
            int current_and = 1;
            for (int i = 0; i < n; i++) {
                current_and &= ((1LL << bit) & a[i]) != 0;
            }

            if (current_and == 1) {
                answer |= (1LL << bit);
                continue;
            }

            // Don't accumulate sum all at once to prevent overflow.
            bool effort_success = true;
            long long previous_k = k;
            auto local_copy_of_a = a;
            for (int i = 0; i < n; i++) {
                if ((1LL << bit) & a[i]) {
                    // If the bit is already set, skip it.
                } else {
                    // (a[i] % 2^bit) is a fancy way to clear higher order
                    // bits
                    long long cost = (1LL << bit) - (a[i] % (1LL << bit));
                    if (k >= cost) {
                        k -= cost;
                    } else {
                        effort_success = false;
                        break;
                    }

                    // If it is possible to turn on this bit, it means that
                    // the new number is 000 (1) 0000.
                    // Not really, because we there could be some set bits in
                    // higher order bits. But then again, we don't care, we
                    // are not gonna use them anyway, since we are using a
                    // trick to clear higher order bits.
                    a[i] = (1LL << bit);
                }
            }

            if (!effort_success) {
                // Reverse all operations
                a = local_copy_of_a;
                k = previous_k;
            } else {
                answer |= (1LL << bit);
            }
        }

        cout << answer << "\n";
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    solve();

    return 0;
}