class NestedLoop {

public static void main(String[] args) {

int n = 5; // 1 step

int m = 7; // 1 step

int sum = 0; // 1 step

for (int i = 0; i < n; i++) { // n steps

for (int j = 0; j < m; j++) { // n*m steps
sum++; // n*m steps

}

}

System.out.println("Sum: " + sum); // 1 step

}

}

how it is came 1+1+1+6n+4+n(6m+4)+3nm+2… (6n+4)…

Course: Data Structures for Coding Interviews in Java - Learn Interactively

Lesson: Example: Time Complexity of an Algorithm With Nested Loops