How do I fix this? I am using C++

Evoid merge(long int arr[], long int 1, long int m, long int r) : long int i, j, k; long int n1 = m - 1 + 1; long int n2 = r - m; long int L[nl], RIn21 for (i = 0; i n1; i++) L[i] arr[1 + 1); | for (j = 0; j n2 ; j++) warning C4244 '-' conversion from double' to 'float', possible loss of data error C2131: expression did not evaluate to a constant note: failure was caused by a read of a variable outside its lifetime note: see usage of 'n1" error C3863: array type 'long [n1]' is not assignable error C3863: array type 'long [n2]' is not assignable : warning C4244: conversion from 'double' to 'float', possible loss of data