运行时错误:引用绑定到类型"int"的未对齐地址0xbebebebebebebec6,这需要 4 个字节对齐 (stl_vector.h)

runtime error: reference binding to misaligned address 0xbebebebebebebec6 for type 'int', which requires 4 byte alignment (stl_vector.h)

本文关键字:对齐 字节 vector stl 0xbebebebebebebec6 绑定 引用 类型 int 运行时错误 地址      更新时间:2023-10-16

我正在编写代码来解决这个问题 在leetcode
上,我解决这个问题的策略是:

  • 为每个单元格索引运行 DFS (x,y(
  • 在每个DFS调用中检查单元格是否为目标单元格
  • 相应地设置标志
  • 如果两个标志都为真,则将此单元格添加到"answers"向量中,否则继续下一个DFS
class Solution {
public:
void psUtil(vector<vector<int> >&mat, int x, int y, int m, int n, int &isP, int &isA, vector<vector<int> >&vis, vector<vector<int> >&ans)
{
//check dstinations
if(x == 0 || y == 0)
{
isP = 1;
}
if(x == m || y == n)
{
isA = 1;
}
vector<int> cell(2);
cell[0] = x;
cell[1] = y;
// check both dst rched
if(isA && isP)
{
// append to ans
ans.push_back(cell);
return;
}
// mark vis
vis.push_back(cell);
int X[] = {-1, 0, 1, 0};
int Y[] = {0, 1, 0, -1};
int x1, y1;
// check feasible neighbours
for(int i = 0; i < 4; ++i)
{
x1 = x + X[i];
y1 = y + Y[i];
if(x1 < 0 || y1 < 0) continue;
if(mat[x1][y1] <= mat[x][y])
{ 
vector<vector<int> > :: iterator it;
vector<int> cell1(2);
cell1[0] = x1;
cell1[1] = y1;
it = find(vis.begin(), vis.end(), cell1);
if(it == vis.end());
else continue;
psUtil(mat, x1, y1, m, n, isP, isA, vis, ans);
if(isA && isP) return; 
}
}
}
vector<vector<int>> pacificAtlantic(vector<vector<int>>& matrix) 
{
// find dimensions
int m = matrix.size(); // rows
int n = matrix[0].size(); // cols
vector<vector<int> >ans;
// flags if rched destinations
int isP, isA;
isP = isA = 0;
// iterate for all indices
for(int x = 0; x < m; ++x)
{
for(int y = 0; y < n; ++y)
{
// visited nested vector
vector<vector<int> >vis; 
psUtil(matrix, x, y, m, n, isP, isA, vis, ans);
isP = isA = 0;    
}
}
return ans;     
}
};

我运行这个的错误是

Runtime Error Message:
Line 924: Char 9: runtime error: reference binding to misaligned address 0xbebebebebebebec6 for type 'int', which requires 4 byte alignment (stl_vector.h)
Last executed input:
[[1,2,2,3,5],[3,2,3,4,4],[2,4,5,3,1],[6,7,1,4,5],[5,1,1,2,4]]

为什么我会收到此消息以及如何解决它?

我发现了我的错误! 这是因为缺少对新计算的坐标的边界检查,以及 psUtil 开头对坐标的边界检查不正确。

取而代之的是:

if(x == m || y == n)
.
.
.
if(x1 < 0 || y1 < 0) continue; 

应该是这样的:

if(x == m-1 || y == n-1)
.
.
.
if(x1 < 0 || y1 < 0 || x1 >= m || y1 >= n) continue;

你的方法很好,但也许我们可以在实现上改进一点。这是使用类似 DFS 方法的公认解决方案。

class Solution {
public:
int direction_row[4] = {0, 1, -1, 0};
int direction_col[4] = {1, 0, 0, -1};
void depth_first_search(vector<vector<int>> &grid, vector<vector<bool>> &visited, int row, int col, int height) {
if (row < 0 || row > grid.size() - 1 || col < 0 || col > grid[0].size() - 1 || visited[row][col])
return;
if (grid[row][col] < height)
return;
visited[row][col] = true;
for (int iter = 0; iter < 4; iter++)
depth_first_search(grid, visited, row + direction_row[iter], col + direction_col[iter], grid[row][col]);
}
vector<vector<int>> pacificAtlantic(vector<vector<int>> &grid) {
vector<vector<int>> water_flows;
int row_length = grid.size();
if (!row_length)
return water_flows;
int col_length = grid[0].size();
vector<vector<bool>> pacific(row_length, vector<bool>(col_length, false));
vector<vector<bool>> atlantic(row_length, vector<bool>(col_length, false));
for (int row = 0; row < row_length; row++) {
depth_first_search(grid, pacific, row, 0, INT_MIN);
depth_first_search(grid, atlantic, row, col_length - 1, INT_MIN);
}
for (int col = 0; col < col_length; col++) {
depth_first_search(grid, pacific, 0, col, INT_MIN);
depth_first_search(grid, atlantic, row_length - 1, col, INT_MIN);
}
for (int row = 0; row < row_length; row++)
for (int col = 0; col < col_length; col++)
if (pacific[row][col] && atlantic[row][col]) {
water_flows.push_back({row, col});
}
return water_flows;
}
};

我也不确定,这是否是太平洋大西洋水流问题最有效的算法。您可以查看讨论板。

<小时 />

参考资料

  • 有关其他详细信息,您可以查看讨论区。其中有很多公认的解决方案、解释、多种语言的高效算法以及时间/空间复杂性分析。

  • 417.太平洋大西洋水流

  • 417. 太平洋大西洋水流 - 讨论