Returns cost of minimum cost path from ( 0 , 0 ) to ( m , n ) in mat [ R ] [ C ]
function minCost ( $ cost , $ m , $ n ) { global $ R ; global $ C ; if ( $ n < 0 $ m < 0 ) return PHP_INT_MAX ; else if ( $ m == 0 && $ n == 0 ) return $ cost [ $ m ] [ $ n ] ; else return $ cost [ $ m ] [ $ n ] + min1 ( minCost ( $ cost , $ m - 1 , $ n - 1 ) , minCost ( $ cost , $ m - 1 , $ n ) , minCost ( $ cost , $ m , $ n - 1 ) ) ; }