2025.1.5——1200

合集 - 日常训练(56)

1.2025.2.19——150002-192.11.23 周六2024-11-243.11.24 周日2024-11-254.11.25 周一日常2024-11-265.2024.11.26 周二日常2024-11-266.2024.11.27 周三2024-11-277.2024.11.28周四2024-11-288.2024.11.29 周五2024-11-299.2024.11.30 周六2024-11-3010.2024.12.1 周日2024-12-0211.2024.12.2 周一2024-12-0212.2024.12.3 周二2024-12-0413.2024.12.4 周三2024-12-0514.2024.12.5 周四2024-12-0615.2024.12.7 周六2024-12-0816.2024.12.8 周日2024-12-0917.2024.12.9 周一2024-12-1018.2024.12.10 周二2024-12-1119.2024.12.11 周三2024-12-1220.2024.12.12 周四2024-12-1321.2024.12.13 周五2024-12-1422.2024.12.14 周六2024-12-1523.2024.12.16 周一2024-12-1724.2024.12.17 周二2024-12-1825.2024.12.18 周三2024-12-1926.2024.12.19 周四2024-12-2027.2024.12.20 周五2024-12-2128.2024.12.21 周六2024-12-2229.2024.12.22 周日2024-12-2330.2024.12.23 周一2024-12-2431.2024.12.24 周四2024-12-2532.2024.12.25 周三2024-12-2633.2024.12.26 周四2024-12-2834.2024.12.27 周五2024-12-2835.2024.12.28 周六2024-12-2936.2024.12.29 周日2024-12-3037.2024.12.30 周一01-01

38.2025.1.5——120001-14

39.2025.1.12——120001-1440.2025.1.14——120001-1541.2025.1.15——120001-1642.2025.1.16——120001-1743.2025.1.17——120001-1844.2025.1.18——130001-1945.2025.1.19——130001-2046.2025.1.20——130001-2147.2025.1.21——130001-2248.2025.1.22——130001-2449.2025.1.24——140001-2650.2025.1.26——140001-2851.2025.2.8——140002-0952.2025.2.9——140002-1153.2025.2.10——140002-1154.2025.2.14——140002-1455.2025.2.15——140002-1556.2025.2.17——140002-17

收起

2025.1.5——1200

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Q1. 1200

Kevin discovered a binary string $s$ that starts with 1 in the river at Moonlit River Park and handed it over to you. Your task is to select two non-empty substrings${}^{\text{∗}}$ of $s$ (which can be overlapped) to maximize the XOR value of these two substrings.

The XOR of two binary strings $a$ and $b$ is defined as the result of the $\oplus$ operation applied to the two numbers obtained by interpreting $a$ and $b$ as binary numbers, with the leftmost bit representing the highest value. Here, $\oplus$ denotes the bitwise XOR operation.

The strings you choose may have leading zeros.

${}^{\text{∗}}$A string $a$ is a substring of a string $b$ if $a$ can be obtained from $b$ by the deletion of several (possibly, zero or all) characters from the beginning and several (possibly, zero or all) characters from the end.

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------------------------独自思考分割线------------------------

• 2025年第一题...

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A1.

1. 1点就是需要发现两个字符串的长度
2. 另一点就是考虑最大值要从高位考虑

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------------------------代码分割线------------------------

A1.

#include <bits/stdc++.h>
#define int long long //
#define endl '\n'     // 交互/调试 关
using namespace std;
#define bug(BUG) cout << "bug:# " << (BUG) << endl
#define bug2(BUG1, BUG2) cout << "bug:# " << (BUG1) << " " << (BUG2) << endl
#define bug3(BUG1, BUG2, BUG3) cout << "bug:# " << (BUG1) << ' ' << (BUG2) << ' ' << (BUG3) << endl
void _();
signed main()
{
    ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
    cout << fixed << setprecision(6);
    int T = 1;
    cin >> T;
    while (T--)
        _();
    return 0;
}

void _()
{
    string s;
    cin >> s;
    int n = s.size();
    s = ' ' + s;
    int has = 1;
    int l = 1, r = n, sub_l = 1, sub_r = 1;
    string t;
    for (int i = 1; i <= n; i++)
        if (s[i] - s[1])
            has = 0;
    if (has)
    {
        cout << l << ' ' << r << ' ' << sub_l << ' ' << sub_r << endl;
        return;
    }

    int f = 0;

    for (int i = 2; i <= n; i++)
        if (!f)
        {
            if (s[i] == '0')
                t += '1', f = 1;
        }
        else
        {
            t += s[i] == '1' ? '0' : '1';
        }
    int m = t.size();
    int res = 0, real_l = 1;
    sub_r = sub_l + m - 1;
    for (; sub_r <= n; sub_l++, sub_r++)
    {
        int ans = 0;
        for (int i = sub_l, j = i - sub_l; i <= sub_r; i++, j++)
            if (s[i] == t[j])
                ans++;
            else
                break;
        if (ans > res)
        {
            res = ans;
            real_l = sub_l;
        }
    }
    sub_l = real_l;
    sub_r = sub_l + m - 1;
    cout << l << ' ' << r << ' ' << sub_l << ' ' << sub_r << endl;
}

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