Error in my hashing code

#1

Please check my code it is shwoing compliation error

Error area is Find method

#2

if(m.find(n-i)!=m.end()){

            swap(m[i],m[(m.find(n-i))->first]);

you have to add this condition before swapping

#3

but it is necessary?
because i will always find that element in the quesiton i am doing

#4

it is always better to check before using find function
because in some case it may not found

#5

can you please tell whats wrong with the code its still giving wrong answer

#6

look at this modified Code

in your code you have make m.first as index and m.second as value
but during find funtion it will search index not value