检查矩阵的所有行是否相互循环旋转
给定一个 n*n 大小的矩阵,任务是找出所有行是否是彼此的圆形旋转。
例子:
Input: mat[][] = 1, 2, 3
3, 1, 2
2, 3, 1
Output: Yes
All rows are rotated permutation
of each other.
Input: mat[3][3] = 1, 2, 3
3, 2, 1
1, 3, 2
Output: No
Explanation : As 3, 2, 1 is not a rotated or
circular permutation of 1, 2, 3
这个想法是基于下面的文章。
检查字符串是否相互旋转的程序
脚步 :
- 创建一个由第一行元素组成的字符串并将该字符串与其自身连接,以便可以有效地执行字符串搜索操作。让这个字符串为 str_cat。
- 遍历所有剩余的行。对于要遍历的每一行,创建一个包含当前行元素的字符串str_curr。如果 str_curr 不是 str_cat 的子字符串,则返回 false。
- 返回真。
下面是上述步骤的实现。
C++
// C++ program to check if all rows of a matrix
// are rotations of each other
#include
using namespace std;
const int MAX = 1000;
// Returns true if all rows of mat[0..n-1][0..n-1]
// are rotations of each other.
bool isPermutedMatrix( int mat[MAX][MAX], int n)
{
// Creating a string that contains elements of first
// row.
string str_cat = "";
for (int i = 0 ; i < n ; i++)
str_cat = str_cat + "-" + to_string(mat[0][i]);
// Concatenating the string with itself so that
// substring search operations can be performed on
// this
str_cat = str_cat + str_cat;
// Start traversing remaining rows
for (int i=1; i
Java
// Java program to check if all rows of a matrix
// are rotations of each other
class GFG
{
static int MAX = 1000;
// Returns true if all rows of mat[0..n-1][0..n-1]
// are rotations of each other.
static boolean isPermutedMatrix(int mat[][], int n)
{
// Creating a string that contains
// elements of first row.
String str_cat = "";
for (int i = 0; i < n; i++)
{
str_cat = str_cat + "-" + String.valueOf(mat[0][i]);
}
// Concatenating the string with itself
// so that substring search operations
// can be performed on this
str_cat = str_cat + str_cat;
// Start traversing remaining rows
for (int i = 1; i < n; i++)
{
// Store the matrix into vector in the form
// of strings
String curr_str = "";
for (int j = 0; j < n; j++)
{
curr_str = curr_str + "-" + String.valueOf(mat[i][j]);
}
// Check if the current string is present in
// the concatenated string or not
if (str_cat.contentEquals(curr_str))
{
return false;
}
}
return true;
}
// Drivers code
public static void main(String[] args)
{
int n = 4;
int mat[][] = {{1, 2, 3, 4},
{4, 1, 2, 3},
{3, 4, 1, 2},
{2, 3, 4, 1}
};
if (isPermutedMatrix(mat, n))
{
System.out.println("Yes");
}
else
{
System.out.println("No");
}
}
}
/* This code contributed by PrinciRaj1992 */
Python3
# Python3 program to check if all rows
# of a matrix are rotations of each other
MAX = 1000
# Returns true if all rows of mat[0..n-1][0..n-1]
# are rotations of each other.
def isPermutedMatrix(mat, n) :
# Creating a string that contains
# elements of first row.
str_cat = ""
for i in range(n) :
str_cat = str_cat + "-" + str(mat[0][i])
# Concatenating the string with itself
# so that substring search operations
# can be performed on this
str_cat = str_cat + str_cat
# Start traversing remaining rows
for i in range(1, n) :
# Store the matrix into vector
# in the form of strings
curr_str = ""
for j in range(n) :
curr_str = curr_str + "-" + str(mat[i][j])
# Check if the current string is present
# in the concatenated string or not
if (str_cat.find(curr_str)) :
return True
return False
# Driver code
if __name__ == "__main__" :
n = 4
mat = [[1, 2, 3, 4],
[4, 1, 2, 3],
[3, 4, 1, 2],
[2, 3, 4, 1]]
if (isPermutedMatrix(mat, n)):
print("Yes")
else :
print("No")
# This code is contributed by Ryuga
C#
// C# program to check if all rows of a matrix
// are rotations of each other
using System;
class GFG
{
//static int MAX = 1000;
// Returns true if all rows of mat[0..n-1,0..n-1]
// are rotations of each other.
static bool isPermutedMatrix(int [,]mat, int n)
{
// Creating a string that contains
// elements of first row.
string str_cat = "";
for (int i = 0; i < n; i++)
{
str_cat = str_cat + "-" + mat[0,i].ToString();
}
// Concatenating the string with itself
// so that substring search operations
// can be performed on this
str_cat = str_cat + str_cat;
// Start traversing remaining rows
for (int i = 1; i < n; i++)
{
// Store the matrix into vector in the form
// of strings
string curr_str = "";
for (int j = 0; j < n; j++)
{
curr_str = curr_str + "-" + mat[i,j].ToString();
}
// Check if the current string is present in
// the concatenated string or not
if (str_cat.Equals(curr_str))
{
return false;
}
}
return true;
}
// Driver code
static void Main()
{
int n = 4;
int [,]mat = {{1, 2, 3, 4},
{4, 1, 2, 3},
{3, 4, 1, 2},
{2, 3, 4, 1}
};
if (isPermutedMatrix(mat, n))
{
Console.WriteLine("Yes");
}
else
{
Console.WriteLine("No");
}
}
}
/* This code contributed by mits */
PHP
Javascript
输出:
Yes