A.2.10. Numeric Algorithms

The numeric algorithms are defined in the numeric header. These algorithms require input iterators; if the algorithm writes output, it uses an output iterator for the destination.

accumulate(beg, end, init)
accumulate(beg, end, init, binaryOp)

Returns the sum of all the values in the input range. The summation starts with the initial value specified by init. The return type is the same type as the type of init. The first version applies the + operator for the element type; the second version applies the specified binary operation.

inner_product(beg1, end1, beg2, init)
inner_product(beg1, end1, beg2, init, binOp1, binOp2)

Returns the sum of the elements generated as the product of two sequences. The two sequences are processed in tandem, and the elements from each sequence are multiplied. The product of that multiplication is summed. The initial value of the sum is specified by init. The type of init determines the return type.

The first version uses the element’s multiplication (*) and addition (+) operators. The second version applies the specified binary operations, using the first operation in place of addition and the second in place of multiplication.

partial_sum(beg, end, dest)
partial_sum(beg, end, dest, binaryOp)

Writes a new sequence to dest in which the value of each new element represents the sum of all the previous elements up to and including its position within the input range. The first version uses the + operator for the element type; the second version applies the specified binary operation. Returns the dest iterator incremented to refer just past the last element written.

adjacent_difference(beg, end, dest)
adjacent_difference(beg, end, dest, binaryOp)

Writes a new sequence to dest in which the value of each new element other than the first represents the difference between the current and previous elements. The first version uses the element type’s - operation; the second version applies the specified binary operation.

iota(beg, end, val)

Assigns val to the first element and increments val. Assigns the incremented value to the next element, and again increments val, and assigns the incremented value to the next element in the sequence. Continues incrementing val and assigning its new value to successive elements in the input sequence.