ให้เมทริกซ์ M[r][c] r = c เป็นเมทริกซ์สี่เหลี่ยมจัตุรัส หาว่าเป็น Diagonal และ Scalar Matrix หรือไม่ หากเป็นพิมพ์ yes
Diagonal matrix
เมทริกซ์สี่เหลี่ยมจัตุรัส m[][] จะเป็น Diagonal Matrix ก็ต่อเมื่อองค์ประกอบนอกแนวทแยงหลักเป็นศูนย์ทั้งหมด
ตัวอย่าง −

องค์ประกอบสีแดงคือแนวทแยงหลักที่ไม่เป็นศูนย์ ส่วนอื่นเป็นศูนย์ จึงเป็น Diagonal Matrix
ตัวอย่าง
Input: m[3][3] = { {7, 0, 0}, {0, 8, 0}, {0, 0, 9}} Output: yes Input: m[3][3] = { {1, 2, 3}, {0, 4, 0}, {0, 0, 5} } Output: noอัลกอริทึม
Start Step 1 -> define macro of size 4 Step 2 -> declare function to check if matrix is diagonal or not bool ifdiagonal(int arr[size][size]) Loop For int i = 0 and i < size and i++ Loop for int j = 0 and j < size and j++ IF ((i != j) & (arr[i][j] != 0)) return false End End End return true step 3 -> In main() Declare and set int arr[size][size] = { { 1, 0, 0, 0 }, { 0, 1, 0, 0 }, { 0, 0, 1, 0 }, { 0, 0, 0, 1 } }; IF (ifdiagonal(arr)) Print its a diagonal matrix End Else Print its not a diagonal matrix End StopDiagonal Matrix
ตัวอย่าง
#include <bits/stdc++.h> #define size 4 using namespace std; // check if matrix is diagonal matrix or not. bool ifdiagonal(int arr[size][size]){ for (int i = 0; i < size; i++) for (int j = 0; j < size; j++) if ((i != j) && (arr[i][j] != 0)) return false; return true; } int main(){ int arr[size][size] = { { 1, 0, 0, 0 }, { 0, 1, 0, 0 }, { 0, 0, 1, 0 }, { 0, 0, 0, 1 } }; if (ifdiagonal(arr)) cout << "its a diagonal matrix" << endl; else cout << "its not a diagonal matrix" << endl; return 0; }ผลลัพธ์
its a diagonal matrix
SCALAR MATRIX
A square matrix m[][] is Scalar Matrix if the elements in the main diagonal are equal and the rest of the elements are zero.
Like in the given example below −

Here, the elements in the red are the diagonal elements which are same and rest elements are zero making it a Scalar Matrix.
Example
Input: m[3][3] = { {2, 0, 0}, {0, 2, 0}, {0, 0, 2} } Output: yes Input: m[3][3] = { {3, 0, 0}, {0, 2, 0}, {0, 0, 3} } Output: noAlgorithm
Start Step 1 -> Declare macro as #define size 4 Step 2 -> declare function to check matrix is scalar matrix or not. bool scalar(int arr[size][size]) Loop For int i = 0 and i < size and i++ Loop For int j = 0 and j < size and j++ IF ((i != j) && (arr[i][j] != 0)) return false End End End Loop for int i = 0 and i < size – 1 and i++ If (arr[i][i] != arr[i + 1][i + 1]) return false End End Return true Step 3 -> In main() Declare array as int arr[size][size] = { { 2, 0, 0, 0 }, { 0, 2, 0, 0 }, { 0, 0, 2, 0 }, { 0, 0, 0, 2 } } IF(scalar(arr)) Print its a scalar matrix Else Print its not a scalar matrix StopExample
#include <bits/stdc++.h> #define size 4 using namespace std; // check matrix is scalar matrix or not. bool scalar(int arr[size][size]){ for (int i = 0; i < size; i++) for (int j = 0; j < size; j++) if ((i != j) && (arr[i][j] != 0)) return false; for (int i = 0; i < size - 1; i++) if (arr[i][i] != arr[i + 1][i + 1]) return false; return true; } int main(){ int arr[size][size] = { { 2, 0, 0, 0 }, { 0, 2, 0, 0 }, { 0, 0, 2, 0 }, { 0, 0, 0, 2 } }; if (scalar(arr)) cout << "its a scalar matrix" << endl; else cout << "its not a scalar matrix" << endl; return 0; }Output
its a scalar matrix