23级新生第四场周赛

题目传送门

A

#include <bits/stdc++.h>

#define int long long
#define endl '\n'
#define vct(a, n, v) std::vector<int>(a)((n)+1,(v))
[[maybe_unused]]const int INF = 0x3f3f3f3f;

void solve () {
    int n;
    std::cin >> n;
    int a[200500] = {0}, b[200500] = {0};
    for (int i = 1; i <= n; i++) std::cin >> a[i];
    for (int i = 1; i <= n; i++) {
        if (i <= n / 2) b[a[i] - i + 100000]++;
        else b[a[i] - (n - i + 1) + 100000]++;
    }
    int ans = 0;
    for (int i = 0; i < 200000; i++) {
        ans = std::max (ans, b[i]);
    }
    std::cout << n - ans << endl;
}

signed main () {
    std::ios::sync_with_stdio (false);
    std::cin.tie (nullptr), std::cout.tie (nullptr);
    int Lazy_boy_ = 1;
//    std::cin >> Lazy_boy_;
    while (Lazy_boy_--)
        solve ();
    return 0;
}

B

#include <bits/stdc++.h>

#define int long long
#define endl '\n'
#define vct(a, n, v) std::vector<int>(a)((n),(v))
[[maybe_unused]]const int INF = 0x3f3f3f3f;

void solve () {
    int n, d, cnt = 0;
    std::cin >> n >> d;
    vct(a, n, 0);
    for (int i = 0; i < n; i++)std::cin >> a[i];
    int ans = 0;
    for (int i = n - 1; i >= 0; i--) {
        int pos = lower_bound (a.begin (), a.end (), a[i] - d) - a.begin ();
        ans += (i - pos) * (i - pos - 1) / 2;
    }
    std::cout << ans << endl;
}

signed main () {
    std::ios::sync_with_stdio (false);
    std::cin.tie (nullptr), std::cout.tie (nullptr);
    int Lazy_boy_ = 1;
//    std::cin >> Lazy_boy_;
    while (Lazy_boy_--)
        solve ();
    return 0;
}

C

#include <bits/stdc++.h>

#define int long long
#define endl '\n'
#define vct(a, n, v) std::vector<int>(a)((n),(v))
[[maybe_unused]]const int INF = 0x3f3f3f3f;

void solve () {
    int n, ans = 0;
    std::cin >> n;
    if (n % 2 == 0) {
        ans = (n / 2) * (n / 2);
    } else {
        ans = ((n + 1) / 2) * (n / 2);
    }
    std::cout << ans << endl;
}

signed main () {
    std::ios::sync_with_stdio (false);
    std::cin.tie (nullptr), std::cout.tie (nullptr);
    int Lazy_boy_ = 1;
    std::cin >> Lazy_boy_;
    while (Lazy_boy_--)
        solve ();
    return 0;
}

D

#include <bits/stdc++.h>

#define int long long
#define endl '\n'
#define vct(a, n, v) std::vector<int>(a)((n),(v))
[[maybe_unused]]const int INF = 0x3f3f3f3f;

void solve () {
    std::string s;
    while (std::cin >> s) {
        auto check = [&] (int i, int j) {
            for (int k = 0; k < (j - i + 1); k++) {
                if (s[k + i] != s[j - k]) {
                    return false;
                }
            }
            return true;
        };
        int ans = 1;
        for (int i = 0; i < (int) s.size (); i++)
            for (int j = i; j < (int) s.size (); j++)
                if (check (i, j))
                    ans = std::max (ans, j - i + 1);
        std::cout << ans << endl;
    }
}

signed main () {
    std::ios::sync_with_stdio (false);
    std::cin.tie (nullptr), std::cout.tie (nullptr);
    int Lazy_boy_ = 1;
//    std::cin >> Lazy_boy_;
    while (Lazy_boy_--)
        solve ();
    return 0;
}

E

#include <bits/stdc++.h>

#define int long long
#define endl '\n'
#define vct(a, n, v) std::vector<int>(a)((n),(v))
[[maybe_unused]]const int INF = 0x3f3f3f3f;

void solve () {
    int n;
    while (std::cin >> n) {
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < n - i - 1; j++)
                std::cout << " ";

            for (int j = 0; j < 2 * i + 1; j++)
                std::cout << "*";
            std::cout << endl;
        }
    }
}

signed main () {
    std::ios::sync_with_stdio (false);
    std::cin.tie (nullptr), std::cout.tie (nullptr);
    int Lazy_boy_ = 1;
//    std::cin >> Lazy_boy_;
    while (Lazy_boy_--)
        solve ();
    return 0;
}

F

#include <bits/stdc++.h>

#define int long long
#define endl '\n'
#define vct(a, n, v) std::vector<int>(a)((n) + 1,(v))
[[maybe_unused]]const int INF = 0x3f3f3f3f;

void solve () {
    int a, b, c, isbn, hash = 0, power = 9;
    char d, e, f, g;
    std::cin >> a >> e >> b >> f >> c >> g >> d;
    isbn = a * pow (10, 8) + b * pow (10, 5) + c;
    while (isbn) {
        hash += (isbn % 10) * power;
        isbn /= 10;
        power -= 1;
    }

    char ans = hash % 11 + '0';
    if (ans == 10 + '0')
        ans = 'X';
    if (ans == d) {
        std::cout << "Right" << endl;
    } else {
        std::cout << a << e << b << f << c << g << ans;
    }
}

signed main () {
    std::ios::sync_with_stdio (false);
    std::cin.tie (nullptr), std::cout.tie (nullptr);
    int Lazy_boy_ = 1;
//    std::cin >> Lazy_boy_;
    while (Lazy_boy_--)
        solve ();
    return 0;
}

G

#include <bits/stdc++.h>

#define int long long
#define endl '\n'
#define vct(a, n, v) std::vector<int>(a)((n) + 1,(v))
[[maybe_unused]]const int INF = 0x3f3f3f3f;

inline __int128 read () {
    __int128 x = 0, f = 1;
    char ch = getchar ();
    while (ch < '0' || ch > '9') {
        if (ch == '-')
            f = -1;
        ch = getchar ();
    }
    while (ch >= '0' && ch <= '9') {
        x = x * 10 + ch - '0';
        ch = getchar ();
    }
    return x * f;
}

inline void print (__int128 x) {
    if (x < 0) {
        putchar ('-');
        x = -x;
    }
    if (x > 9)
        print (x / 10);
    putchar (x % 10 + '0');
}

void solve () {
    __int128 a = read(), b = read();
    print (a * b / std::__gcd (a, b));
}

signed main () {
    std::ios::sync_with_stdio (false);
    std::cin.tie (nullptr), std::cout.tie (nullptr);
    int Lazy_boy_ = 1;
//    std::cin >> Lazy_boy_;
    while (Lazy_boy_--)
        solve ();
    return 0;
}

H

#include <bits/stdc++.h>

#define int long long
#define endl '\n'
#define vct(a, n, v) std::vector<int>(a)((n) + 1,(v))
[[maybe_unused]]const int INF = 0x3f3f3f3f;

void solve () {
    int a, b, cnt = 0;
    int s[] = {1, 0, 0, 0, 1, 0, 1, 0, 2, 1};
    std::cin >> a >> b;
    for (int i = a; i <= b; i++) {
        int w = i;
        while (w) {
            int k = w % 10;
            cnt += s[k];
            w /= 10;
        }
    }
    std::cout << cnt << endl;
}

signed main () {
    std::ios::sync_with_stdio (false);
    std::cin.tie (nullptr), std::cout.tie (nullptr);
    int Lazy_boy_ = 1;
    std::cin >> Lazy_boy_;
    while (Lazy_boy_--)
        solve ();
    return 0;
}

I

#include <bits/stdc++.h>

#define int long long
#define endl '\n'
#define vct(a, n, v) std::vector<int>(a)((n) + 1,(v))
[[maybe_unused]]const int INF = 0x3f3f3f3f;

void solve () {
    int n, x, ans = 0;
    std::cin >> n;
    vct (a, 1000500, 0);
    vct (s, 1000500, 0);
    for (int i = 1; i <= n; i++) std::cin >> x, s[i] = s[i - 1] + x;
    a[0] = 1;
    for (int i = 1; i <= n; i++) {
        for (int j = 0; j * j <= s[i]; j++) {
            ans += a[s[i] - j * j];
        }
        a[s[i]]++;
    }
    std::cout << ans << endl;
}

signed main () {
    std::ios::sync_with_stdio (false);
    std::cin.tie (nullptr), std::cout.tie (nullptr);
    int Lazy_boy_ = 1;
//    std::cin >> Lazy_boy_;
    while (Lazy_boy_--)
        solve ();
    return 0;