Program to check if matrix is upper triangular | PHP Program to check upper triangular matrix . ; Function to check matrix is in upper triangular form or not . ; Driver Code
< ? php $ N = 4 ; function isUpperTriangularMatrix ( $ mat ) { global $ N ; for ( $ i = 1 ; $ i < $ N ; $ i ++ ) for ( $ j = 0 ; $ j < $ i ; $ j ++ ) if ( $ mat [ $ i ] [ $ j ] != 0 ) return false ; return true ; } $ mat = array ( array ( 1 , 3 , 5 , 3 ) , array ( 0 , 4 , 6 , 2 ) , array ( 0 , 0 , 2 , 5 ) , array ( 0 , 0 , 0 , 6 ) ) ; if ( isUpperTriangularMatrix ( $ mat ) ) echo " Yes " ; else echo " No " ; ? >