leetcode73 矩阵置零

题目描述

给定一个 m x n 的矩阵，如果一个元素为 0 ，则将其所在行和列的所有元素都设为 0 。请使用原地算法。
输入：matrix = [[1,1,1],[1,0,1],[1,1,1]]
输出：[[1,0,1],[0,0,0],[1,0,1]]
输入：matrix = [[0,1,2,0],[3,4,5,2],[1,3,1,5]]
输出：[[0,0,0,0],[0,4,5,0],[0,3,1,0]]

python完整代码

class Solution:
    def setZeroes(self, matrix):
        rows = len(matrix)  # 获取矩阵的行数
        cols = len(matrix[0])  # 获取矩阵的列数

        # 定义两个集合用于存储应该置零的行号和列号
        zero_rows = set()
        zero_cols = set()

        # 遍历整个矩阵，记录0元素所在的行和列
        for i in range(rows):
            for j in range(cols):
                if matrix[i][j] == 0:
                    zero_rows.add(i)
                    zero_cols.add(j)

        # 将需要置零的行和列的元素置为0
        for i in range(rows):
            for j in range(cols):
                if i in zero_rows or j in zero_cols:  # 如果i和j在元素0所在的行或列
                    matrix[i][j] = 0


if __name__ == "__main__":
    solution = Solution()

    # 测试用例1：矩阵中有0元素
    matrix1 = [
        [1, 1, 1],
        [1, 0, 1],
        [1, 1, 1]
    ]
    print("原始矩阵1：")
    for row in matrix1:
        print(row)
    solution.setZeroes(matrix1)
    print("\n置零后的矩阵1：")
    for row in matrix1:
        print(row)

    # 测试用例2：矩阵中没有0元素
    matrix2 = [
        [0, 1, 2, 0],
        [3, 4, 5, 2],
        [1, 3, 1, 5]
    ]
    print("\n原始矩阵2：")
    for row in matrix2:
        print(row)
    solution.setZeroes(matrix2)
    print("\n置零后的矩阵2：")
    for row in matrix2:
        print(row)

    # 测试用例3：矩阵中全是0元素
    matrix3 = [
        [0, 0, 0],
        [0, 0, 0],
        [0, 0, 0]
    ]
    print("\n原始矩阵3：")
    for row in matrix3:
        print(row)
    solution.setZeroes(matrix3)
    print("\n置零后的矩阵3：")
    for row in matrix3:
        print(row)

class Solution:
    def setZeroes(self, matrix):
        rows = len(matrix)  # 获取矩阵的行数
        cols = len(matrix[0])  # 获取矩阵的列数

        # 定义两个标志位，用于标记第一行和第一列是否需要置零
        first_row_zero = False
        first_col_zero = False

        # 检查第一行是否有0元素
        for j in range(cols):
            if matrix[0][j] == 0:
                first_row_zero = True
                break

        # 检查第一列是否有0元素
        for i in range(rows):
            if matrix[i][0] == 0:
                first_col_zero = True
                break

        # 遍历除第一行和第一列以外的元素，若为0，则将对应的第一行和第一列置为0
        for i in range(1, rows):
            for j in range(1, cols):
                if matrix[i][j] == 0:
                    matrix[i][0] = 0
                    matrix[0][j] = 0

        # 根据第一行和第一列的标志位，将对应的行和列置为0
        for i in range(1, rows):
            for j in range(1, cols):
                if matrix[i][0] == 0 or matrix[0][j] == 0:
                    matrix[i][j] = 0

        # 如果第一行需要置零，则将第一行置零
        if first_row_zero:
            for j in range(cols):
                matrix[0][j] = 0

        # 如果第一列需要置零，则将第一列置零
        if first_col_zero:
            for i in range(rows):
                matrix[i][0] = 0



if __name__ == "__main__":
    solution = Solution()

    # 测试用例1：矩阵中有0元素
    matrix1 = [
        [1, 1, 1],
        [1, 0, 1],
        [1, 1, 1]
    ]
    print("原始矩阵1：")
    for row in matrix1:
        print(row)
    solution.setZeroes(matrix1)
    print("\n置零后的矩阵1：")
    for row in matrix1:
        print(row)

    # 测试用例2：矩阵中没有0元素
    matrix2 = [
        [0, 1, 2, 0],
        [3, 4, 5, 2],
        [1, 3, 1, 5]
    ]
    print("\n原始矩阵2：")
    for row in matrix2:
        print(row)
    solution.setZeroes(matrix2)
    print("\n置零后的矩阵2：")
    for row in matrix2:
        print(row)

    # 测试用例3：矩阵中全是0元素
    matrix3 = [
        [0, 0, 0],
        [0, 0, 0],
        [0, 0, 0]
    ]
    print("\n原始矩阵3：")
    for row in matrix3:
        print(row)
    solution.setZeroes(matrix3)
    print("\n置零后的矩阵3：")
    for row in matrix3:
        print(row)

c++完整代码

#include <iostream>
#include <vector>
#include <unordered_set>

using namespace std;

class Solution {
public:
    void setZeroes(vector<vector<int>>& matrix) {
        int rows = matrix.size(); // 获取矩阵的行数
        int cols = matrix[0].size(); // 获取矩阵的列数

        // 定义两个集合用于存储应该置零的行号和列号
        unordered_set<int> zero_rows;
        unordered_set<int> zero_cols;

        // 遍历整个矩阵，记录0元素所在的行和列
        for (int i = 0; i < rows; ++i) {
            for (int j = 0; j < cols; ++j) {
                if (matrix[i][j] == 0) {
                    zero_rows.insert(i);
                    zero_cols.insert(j);
                }
            }
        }

        // 将需要置零的行和列的元素置为0
        for (int i = 0; i < rows; ++i) {
            for (int j = 0; j < cols; ++j) {
                if (zero_rows.count(i) || zero_cols.count(j)) {  // 如果i和j在元素0所在的行或列
                    matrix[i][j] = 0;
                }
            }
        }
    }
};

int main() {
    Solution solution;

    // 测试用例1：矩阵中有0元素
    vector<vector<int>> matrix1 = {
            {1, 1, 1},
            {1, 0, 1},
            {1, 1, 1}
    };
    cout << "matrix 1:" << endl;
    for (auto& row : matrix1) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    solution.setZeroes(matrix1);
    cout << "after matrix 1:" << endl;
    for (auto& row : matrix1) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    vector<vector<int>> matrix2 = {
            {0, 1, 2, 0},
            {3, 4, 5, 2},
            {1, 3, 1, 5}
    };
    cout << "matrix 2:" << endl;
    for (auto& row : matrix2) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    solution.setZeroes(matrix2);
    cout << "after matrix 2:" << endl;
    for (auto& row : matrix2) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    vector<vector<int>> matrix3 = {
            {0, 1, 0},
            {1, 0, 1},
            {0, 1, 0}
    };
    cout << "matrix 3:" << endl;
    for (auto& row : matrix3) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    solution.setZeroes(matrix3);
    cout << "after matrix 3:" << endl;
    for (auto& row : matrix3) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }

    return 0;
}

#include <iostream>
#include <vector>

using namespace std;

class Solution {
public:
void setZeroes(vector<vector<int>>& matrix) {
    int rows = matrix.size(); // 获取矩阵的行数
    int cols = matrix[0].size(); // 获取矩阵的列数

    // 定义两个标志位，用于标记第一行和第一列是否需要置零
    bool first_row_zero = false;
    bool first_col_zero = false;

    // 检查第一行是否有0元素
    for (int j = 0; j < cols; ++j) {
        if (matrix[0][j] == 0) {
            first_row_zero = true;
            break;
        }
    }

    // 检查第一列是否有0元素
    for (int i = 0; i < rows; ++i) {
        if (matrix[i][0] == 0) {
            first_col_zero = true;
            break;
        }
    }

    // 遍历除第一行和第一列以外的元素，若为0，则将对应的第一行和第一列置为0
    for (int i = 1; i < rows; ++i) {
        for (int j = 1; j < cols; ++j) {
            if (matrix[i][j] == 0) {
                matrix[i][0] = 0;
                matrix[0][j] = 0;
            }
        }
    }

    // 根据第一行和第一列的标志位，将对应的行和列置为0
    for (int i = 1; i < rows; ++i) {
        for (int j = 1; j < cols; ++j) {
            if (matrix[i][0] == 0 || matrix[0][j] == 0) {
                matrix[i][j] = 0;
            }
        }
    }

    // 如果第一行需要置零，则将第一行置零
    if (first_row_zero) {
        for (int j = 0; j < cols; ++j) {
            matrix[0][j] = 0;
        }
    }

    // 如果第一列需要置零，则将第一列置零
    if (first_col_zero) {
        for (int i = 0; i < rows; ++i) {
            matrix[i][0] = 0;
        }
    }
}
};

int main() {
    Solution solution;

    // 测试用例
    vector<vector<int>> matrix1 = {
    {1, 1, 1},
    {1, 0, 1},
    {1, 1, 1}
};
    cout << "matrix 1:" << endl;
    for (auto& row : matrix1) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    solution.setZeroes(matrix1);
    cout << "after matrix 1:" << endl;
    for (auto& row : matrix1) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    vector<vector<int>> matrix2 = {
    {0, 1, 2, 0},
    {3, 4, 5, 2},
    {1, 3, 1, 5}
};
    cout << "matrix 2:" << endl;
    for (auto& row : matrix2) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    solution.setZeroes(matrix2);
    cout << "after matrix 2:" << endl;
    for (auto& row : matrix2) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    vector<vector<int>> matrix3 = {
    {0, 1, 0},
    {1, 0, 1},
    {0, 1, 0}
};
    cout << "matrix 3:" << endl;
    for (auto& row : matrix3) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    solution.setZeroes(matrix3);
    cout << "after matrix 3:" << endl;
    for (auto& row : matrix3) {
        for (int val : row) {
            cout << val << " ";
        }
        cout << endl;
    }
    return 0;
}

Java完整代码

import java.util.HashSet;
import java.util.Set;
public class setZeroes {
    public void setZeroes1(int[][] matrix) {
        int rows = matrix.length; // 获取矩阵的行数
        int cols = matrix[0].length; // 获取矩阵的列数

        // 定义两个集合用于存储应该置零的行号和列号
        Set<Integer> zeroRows = new HashSet<>();
        Set<Integer> zeroCols = new HashSet<>();

        // 遍历整个矩阵，记录0元素所在的行和列
        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                if (matrix[i][j] == 0) {
                    zeroRows.add(i);
                    zeroCols.add(j);
                }
            }
        }

        // 将需要置零的行和列的元素置为0
        for (int i = 0; i < rows; i++) {
            for (int j = 0; j < cols; j++) {
                if (zeroRows.contains(i) || zeroCols.contains(j)) {  // 如果i和j在元素0所在的行或列
                    matrix[i][j] = 0;
                }
            }
        }
    }

    public static void main(String[] args) {
        setZeroes setZeroes1 = new setZeroes();

        // 测试用例1：矩阵中有0元素
        int[][] matrix1 = {
                {1, 1, 1},
                {1, 0, 1},
                {1, 1, 1}
        };
        System.out.println("原始矩阵1：");
        for (int[] row : matrix1) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }
        setZeroes1.setZeroes1(matrix1);
        System.out.println("\n置零后的矩阵1：");
        for (int[] row : matrix1) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }

        int[][] matrix2 = {
                {0, 1, 2, 0},
                {3, 4, 5, 2},
                {1, 3, 1, 5}
        };
        System.out.println("原始矩阵2：");
        for (int[] row : matrix2) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }

        setZeroes1.setZeroes1(matrix2);
        System.out.println("\n置零后的矩阵2：");
        for (int[] row : matrix2) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }

        int[][] matrix3 = {
                {0, 1, 0},
                {1, 0, 1},
                {0, 1, 0}
        };
        System.out.println("原始矩阵3：");
        for (int[] row : matrix3) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }

        setZeroes1.setZeroes1(matrix3);
        System.out.println("\n置零后的矩阵3：");
        for (int[] row : matrix3) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }
    }
}

import java.util.HashSet;
import java.util.Set;

public class setZeroes2 {
    public void setZeroes(int[][] matrix) {
        int rows = matrix.length;  // 获取矩阵的行数
        int cols = matrix[0].length;  // 获取矩阵的列数

        // 定义两个标志位，用于标记第一行和第一列是否需要置零
        boolean firstRowZero = false;
        boolean firstColZero = false;

        // 检查第一行是否有0元素
        for (int j = 0; j < cols; j++) {
            if (matrix[0][j] == 0) {
                firstRowZero = true;
                break;
            }
        }

        // 检查第一列是否有0元素
        for (int i = 0; i < rows; i++) {
            if (matrix[i][0] == 0) {
                firstColZero = true;
                break;
            }
        }

        // 遍历除第一行和第一列以外的元素，若为0，则将对应的第一行和第一列置为0
        for (int i = 1; i < rows; i++) {
            for (int j = 1; j < cols; j++) {
                if (matrix[i][j] == 0) {
                    matrix[i][0] = 0;
                    matrix[0][j] = 0;
                }
            }
        }

        // 根据第一行和第一列的标志位，将对应的行和列置为0
        for (int i = 1; i < rows; i++) {
            for (int j = 1; j < cols; j++) {
                if (matrix[i][0] == 0 || matrix[0][j] == 0) {
                    matrix[i][j] = 0;
                }
            }
        }

        // 如果第一行需要置零，则将第一行置零
        if (firstRowZero) {
            for (int j = 0; j < cols; j++) {
                matrix[0][j] = 0;
            }
        }

        // 如果第一列需要置零，则将第一列置零
        if (firstColZero) {
            for (int i = 0; i < rows; i++) {
                matrix[i][0] = 0;
            }
        }
    }

    public static void main(String[] args) {
        setZeroes2 setZeroes = new setZeroes2();

        // 测试用例1：矩阵中有0元素
        int[][] matrix1 = {
                {1, 1, 1},
                {1, 0, 1},
                {1, 1, 1}
        };
        System.out.println("原始矩阵1：");
        for (int[] row : matrix1) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }
        setZeroes.setZeroes(matrix1);
        System.out.println("\n置零后的矩阵1：");
        for (int[] row : matrix1) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }

        int[][] matrix2 = {
                {0, 1, 2, 0},
                {3, 4, 5, 2},
                {1, 3, 1, 5}
        };
        System.out.println("原始矩阵2：");
        for (int[] row : matrix2) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }

        setZeroes.setZeroes(matrix2);
        System.out.println("\n置零后的矩阵2：");
        for (int[] row : matrix2) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }

        int[][] matrix3 = {
                {0, 1, 0},
                {1, 0, 1},
                {0, 1, 0}
        };
        System.out.println("原始矩阵3：");
        for (int[] row : matrix3) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }

        setZeroes.setZeroes(matrix3);
        System.out.println("\n置零后的矩阵3：");
        for (int[] row : matrix3) {
            for (int val : row) {
                System.out.print(val + " ");
            }
            System.out.println();
        }
    }
}