Codeforces——1A Theatre Square

小声BB

第一次做1000的题目，心里还是有点没底的，也是错了两次才AC

题干

time limit per test：1 second memory limit per test：256 megabytes input：standard input output：standard output

Theatre Square in the capital city of Berland has a rectangular shape with the size n × m meters. On the occasion of the city’s anniversary, a decision was taken to pave the Square with square granite flagstones. Each flagstone is of the size a × a.

What is the least number of flagstones needed to pave the Square? It’s allowed to cover the surface larger than the Theatre Square, but the Square has to be covered. It’s not allowed to break the flagstones. The sides of flagstones should be parallel to the sides of the Square. Input

The input contains three positive integer numbers in the first line: n,  m and a (1 ≤  n, m, a ≤ 10^9). Output

Write the needed number of flagstones.

Examples Input 6 6 4

Output 4

分析

这道题开始有些数据上的难度了，三个变量都是10的9次 题目是说一个n×m的广场用a×a的石头去铺，至少几块铺满，那么很明显是(n/a)*(m/a)，都是不舍进位的，主要的坑也就只是数据上的难度，10的18次就要用到long long，不放心的话可以unsigned

代码

#include<iostream> #include<string.h> using namespace std; int main() { unsigned long long n,m,a; cin>> n >> m >> a; cout << ((n + a - 1) / a) * ((m + a - 1) / a); return 0; }