Submission #779303

#	Time	Username	Problem	Language	Result	Execution time	Memory
779303		vjudge1	Aliens (IOI07_aliens)	C++17	100 / 100	2 ms	208 KiB

aliens

#include <iostream>
#include <cstring>
using namespace std;
string answer;
void speedy()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
}
int inside(long long n, long long x, long long y)
{
    if (1 <= x && x <= n && 1 <= y && y <= n)
        return 1;
    return 0;
}
int main()
{
    speedy();
    long long n, x0, y0, step, left, right;
    int pp;
    cin >> n >> x0 >> y0;
    ///find xL
    step = 1;
    long long xL_out = x0 - step, xL_in = x0;
    pp = 0;
    while (pp == 0)
    {
        if (inside(n, xL_out, y0) == 0)
            pp = 1;
        else
        {
            cout << "examine " << xL_out << ' ' << y0 << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                pp = 1;
            else
            {
                xL_in = xL_out;
                step = step * 2;
                xL_out = xL_out - step;
            }
        }
    }
    left = xL_out, right = xL_in;
    long long xL;
    while (left <= right)
    {
        long long mid = (left + right) / 2;
        if (inside(n, mid, y0) == 0)
            left = mid + 1;
        else
        {
            cout << "examine " << mid << ' ' << y0 << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                left = mid + 1;
            else
            {
                right = mid - 1;
                xL = mid;
            }
        }
    }
    ///find xR
    step = 1;
    long long xR_out = x0 + step, xR_in = x0;
    pp = 0;
    while (pp == 0)
    {
        if (inside(n, xR_out, y0) == 0)
            pp = 1;
        else
        {
            cout << "examine " << xR_out << ' ' << y0 << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                pp = 1;
            else
            {
                xR_in = xR_out;
                step = step * 2;
                xR_out = xR_out + step;
            }
        }
    }
    left = xR_in, right = xR_out;
    long long xR;
    while (left <= right)
    {
        long long mid = (left + right) / 2;
        if (inside(n, mid, y0) == 0)
            right = mid - 1;
        else
        {
            cout << "examine " << mid << ' ' << y0 << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                right = mid - 1;
            else
            {
                left = mid + 1;
                xR = mid;
            }
        }
    }
    ///find yU
    step = 1;
    long long yU_out = y0 + step, yU_in = y0;
    pp = 0;
    while (pp == 0)
    {
        if (inside(n, x0, yU_out) == 0)
            pp = 1;
        else
        {
            cout << "examine " << x0 << ' ' << yU_out << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                pp = 1;
            else
            {
                yU_in = yU_out;
                step = step * 2;
                yU_out = yU_out + step;
            }
        }
    }
    left = yU_in, right = yU_out;
    long long yU;
    while (left <= right)
    {
        long long mid = (left + right) / 2;
        if (inside(n, x0, mid) == 0)
            right = mid - 1;
        else
        {
            cout << "examine " << x0 << ' ' << mid << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                right = mid - 1;
            else
            {
                left = mid + 1;
                yU = mid;
            }
        }
    }
    ///find m, xC, yC
    long long m = xR - xL + 1, xC = xL + m / 2, yC = yU - m / 2;
    ///find center
    long long goL = 0;
    pp = 0;
    while (pp == 0)
    {
        if (inside(n, xC - 2 * m * (goL + 1), yC) == 0)
            pp = 1;
        else
        {
            cout << "examine " << xC - 2 * m * (goL + 1) << ' ' << yC << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                 pp = 1;
            else
                goL++;
        }
    }
    long long goR = 0;
    pp = 0;
    while (pp == 0)
    {
        if (inside(n, xC + 2 * m * (goR + 1), yC) == 0)
            pp = 1;
        else
        {
            cout << "examine " << xC + 2 * m * (goR + 1) << ' ' << yC << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                 pp = 1;
            else
                goR++;
        }
    }
    long long goD = 0;
    pp = 0;
    while (pp == 0)
    {
        if (inside(n, xC, yC - 2 * m * (goD + 1)) == 0)
            pp = 1;
        else
        {
            cout << "examine " << xC << ' ' << yC - 2 * m * (goD + 1) << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                 pp = 1;
            else
                goD++;
        }
    }
    long long goU = 0;
    pp = 0;
    while (pp == 0)
    {
        if (inside(n, xC, yC + 2 * m * (goU + 1)) == 0)
            pp = 1;
        else
        {
            cout << "examine " << xC << ' ' << yC + 2 * m * (goU + 1) << '\n' << flush;
            cin >> answer;
            if (answer == "false")
                 pp = 1;
            else
                goU++;
        }
    }
    cout << "solution " << xC + goR * m - goL * m << ' ' << yC + goU * m - goD * m << '\n' << flush;
    return 0;
}

Compilation message (stderr)

aliens.cpp: In function 'int main()':
aliens.cpp:150:49: warning: 'yU' may be used uninitialized in this function [-Wmaybe-uninitialized]
  150 |     long long m = xR - xL + 1, xC = xL + m / 2, yC = yU - m / 2;
      |                                                 ^~
aliens.cpp:150:22: warning: 'xR' may be used uninitialized in this function [-Wmaybe-uninitialized]
  150 |     long long m = xR - xL + 1, xC = xL + m / 2, yC = yU - m / 2;
      |                   ~~~^~~~
aliens.cpp:150:32: warning: 'xL' may be used uninitialized in this function [-Wmaybe-uninitialized]
  150 |     long long m = xR - xL + 1, xC = xL + m / 2, yC = yU - m / 2;
      |                                ^~

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10