512. CNG Refill
Baburao has planned a circular route with his girlfriend on her birthday. Along this route, there are n CNG stations, each with a certain amount of CNG represented by cng[i] at the ith station. Baburao's car has an unlimited capacity CNG tank, and it costs price[i] of CNG to travel from the ith station to the next (i+1)th station. Baburao will start the journey with an empty tank at one of the CNG stations. Help him determine the starting station.
Given two integer arrays cng and price, input the size of the cng and price arrays.
If Baburao can travel around the circular route once in the clockwise direction, return the starting CNG station's index. Otherwise, return -1.
5 1 2 3 4 5 5 3 4 5 1 2
n == m == cng.length == price.length 1 <= n <= 105 0 <= cng[i], price[i] <= 104