text: Optimized C program for n 'th perrin number
code: #include <stdio.h> NEW_LINE int per ( int n ) { int a = 3 , b = 0 , c = 2 , i ; int m ; if ( n == 0 ) return a ; if ( n == 1 ) return b ; if ( n == 2 ) return c ; while ( n > 2 ) { m = a + b ; a = b ; b = c ; c = m ; n -- ; } return m ; }