// 2579. Count Total Number of Colored Cells #include "leetcode.h" /* * there exists an infinitely large two-dimensional grid of uncoloured unit * cells. you are given a positive integer 'n', indicating that you must do the * following routine for 'n' minutes: at the first minute, colour any arbitrary * unit cell blue, and every minute thereafter, colour blue every uncoloured * cell that touches a blue cell. */ long long coloredCells(int n) { return 2L * n * (n - 1) + 1; } int main() { printf("%lld\n", coloredCells(1)); // expect: 1 printf("%lld\n", coloredCells(2)); // expect: 5 }