Discription
NB : An is a triangular matrix with all elements equal to 0 above the main diagonal.
Sample input 1:
3
1 0 0
4 5 0
7 8 9
Sample output 1:
Yes
Sample input 2:
3
0 1 0
0 0 0
0 0 0
Sample output 2:
No
C
#include <stdio.h>
int main()
{
int n;
scanf("%d",&n);
int mat[n][n];
for(int i = 0 ; i<n ; i++){
for(int j = 0 ; j<n ; j++){
scanf("%d",&mat[i][j]) ;
}
}
int flag = 1;
for(int i = 0 ; i<n ; i++){
for(int j = i+1 ; j<n ; j++){
if(mat[i][j] != 0){
flag = 0;
break;
}
}
if(flag == 0)
{
break;
}
}
if(flag == 1)
{
printf("Yes");
}
else
{
printf("No");
}
return 0;
}
C++
#include <bits/stdc++.h>
using namespace std;
int main()
{
int n;
cin>>n;
int mat[n][n];
for(int i = 0 ; i<n ; i++){
for(int j = 0 ; j<n ; j++){
cin>>mat[i][j];
}
}
bool flag = true;
for(int i = 0 ; i<n ; i++){
for(int j = i+1 ; j<n ; j++){
if(mat[i][j] != 0){
flag = false;
break;
}
}
if(!flag)
{
break;
}
}
if(flag)
{
cout<<"Yes";
}
else
{
cout<<"No";
}
return 0;
}
JAVA
import java.util.*;
import java.lang.*;
import java.io.*;
class Main
{
public static void main (String[] args) throws java.lang.Exception
{
Scanner sc=new Scanner(System.in);
int n = sc.nextInt();
int mat[][] = new int[n][n];
for(int i = 0 ; i<n ; i++){
for(int j = 0 ; j<n ; j++){
mat[i][j] = sc.nextInt();
}
}
boolean flag = true;
for(int i = 0 ; i<n ; i++){
for(int j = i+1 ; j<n ; j++){
if(mat[i][j] != 0){
flag = false;
break;
}
}
if(!flag)
{
break;
}
}
if(flag)
{
System.out.println("Yes");
}
else
{
System.out.println("No");
}
}
}
PYTHON
def IsLowerTri(a):
for i in range(0, len(a)):
for j in range(i+1, len(a)):
if(a[i][j] != 0):
return False
return True
a = [[1,9,0],
[4,5,0],
[7,8,9]];
if IsLowerTri(a):
print ("Yes")
else:
print ("No")
