nested for loop
for (i = 0; i < n; i + +) {
for (j = 0; j < m; j + +) {
sequence of statements
}
Here, we observe that, the outer loop executes n times. Every time the outer loop executes, the inner loop executes m times. Consequently of this, statements in the inner loop execute a total of n * m times. Thus, the time complexity is O(n * m). If we modify the conditional variables, where the condition of the inner loop is j < n instead of j < m (i.e., the inner loop also executes n times), then the total complexity for the nested loop is O(n2).