is_sorted()
Function
Returns true if the range [first,last) is sorted into ascending order.
Declaration
is_sorted(first,last);
where, first, last: Input iterators to the initial and final positions of the first sorted sequence.The range used is [first,last), which contains all the elements between first1 and last1, including the element pointed by first but not the element pointed by last.
Return value:
true if the range [first,last) is sorted into ascending order, false otherwise. If the range [first,last) contains less than two elements, the function always returns true.
Example
// is_sorted example
#include <iostream>
#include <algorithm> //is_sorted,prev_permutation
#include <array> // array
using namespace std;
int main () {
array<int,4> arr {2,4,1,3};
do {
prev_permutation(arr.begin(),arr.end());
for (int& x:arr) std::cout <<' '<< x;
cout<<endl;
} while (!is_sorted(arr.begin(),arr.end()));
cout << "is_sorted returned true!";
return 0;
}
Output:
2 3 4 1
2 3 1 4
2 1 4 3
2 1 3 4
1 4 3 2
1 4 2 3
1 3 4 2
1 3 2 4
1 2 4 3
1 2 3 4
is_sorted returned true!