#include <stdio.h> unsigned long long add = 2, diff = 2, ans[1000001] = {0, 0, 0, 0, 1}; int main() { int n; for (n = 5; n <= 1000000; n++) { ans[n] = ans[n - 1] + add; add += diff; diff += !(n & 1); } while (scanf("%d", &n) && n >= 3) { printf("%llu\n", ans[n]); } return 0; }
沒有留言:
張貼留言