Submission #75093420

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Source Code Expand

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

int dx[] = {-1, 0, 0, 1};
int dy[] = {0, -1, 1, 0};
char dc[] = {'U', 'L', 'R', 'D'};

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int t;
    cin >> t;
    while (t--)
    {
        int n, a, b;
        cin >> n >> a >> b;

        if ((a + b) % 2 == 0)
        { // 正确判断，替换你错误的 n%2==1
            cout << "No\n";
            continue;
        }

        cout << "Yes\n";
        vector<vector<int>> vis(n + 1, vector<int>(n + 1, 0));
        int x = 1, y = 1;
        vis[x][y] = 1;
        string path;
        path.reserve(n * n); 

        for (int step = 0; step < n * n - 2; step++)
        {
            int maxdist = -1;
            int best = -1, nx, ny;

            for (int i = 0; i < 4; i++)
            {
                int xx = x + dx[i];
                int yy = y + dy[i];
                if (xx < 1 || xx > n || yy < 1 || yy > n)
                    continue;
                if (xx == a && yy == b)
                    continue;
                if (vis[xx][yy])
                    continue;

                int d = (n - xx) * (n - xx) + (n - yy) * (n - yy);
                if (d > maxdist)
                {
                    maxdist = d;
                    best = i;
                    nx = xx;
                    ny = yy;
                }
            }

            path += dc[best];
            vis[nx][ny] = 1;
            x = nx;
            y = ny;

            if (x == n && y == n)
                break;
        }

        cout << path << '\n';
    }
    return 0;
}

Submission Info

Compile Error

./Main.cpp: In function 'main':
./Main.cpp:64:13: warning: 'nx' may be used uninitialized [-Wmaybe-uninitialized]
   64 |             if (x == n && y == n)
      |             ^
./Main.cpp:36:28: note: 'nx' was declared here
   36 |             int best = -1, nx, ny;
      |                            ^
./Main.cpp:60:23: warning: 'ny' may be used uninitialized [-Wmaybe-uninitialized]
   60 |             vis[nx][ny] = 1;
      |                       ^
./Main.cpp:36:32: note: 'ny' was declared here
   36 |             int best = -1, nx, ny;
      |                                ^

Judge Result