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# Two Dimensional Arrays ( array2 )

Definition

An instance A of the parameterized data type array2<E> is a mapping from a set of pairs I = [a..b] x [c..d] , called the index set of A , to the set of variables of data type E , called the element type of A , for two fixed intervals of integers [a..b] and [c..d] . A(i, j) is called the element at position (i, j) .

#include < LEDA/core/array2.h >

Creation

 array2< E> A(int a, int b, int c, int d) creates an instance A of type array2 with index set [a..b] x [c..d] . array2< E> A(int n, int m) creates an instance A of type array2 with index set [0..n - 1] x [0..m - 1] .

Operations

 void A.init(const E& x) assigns x to each element of A . E& A(int i, int j) returns A(i, j) . Precondition a < = i < = b and c < = j < = d . int A.low1() returns a . int A.high1() returns b . int A.low2() returns c . int A.high2() returns d .

Implementation

Two dimensional arrays are implemented by C++vectors. All operations take time O(1) , the space requirement is O(I*sizeof (E)) .     Next: Stacks ( stack ) Up: Basic Data Types Previous: Basic Data Types   Contents   Index
Christian Uhrig 2017-04-07