USACO算法系列二十二——fence9

    题目：http://www.nocow.cn/index.php/Translate:USACO/fence9

    皮克定理：S = A + B/2 -1；S 面积， B 边上的点数， A 多边形内部点数。

    边上点数计算公式gcd（a, b) + 1.

    因此这道题就很简单了。使用宏定义嚣张了一把，不过没使用好，浪费了不少调式时间。唉……要奋进啊

#include <iostream>#include <fstream>#define max(a,b) ((a)>(b)?(a):(b))#define min(a,b) ((a)<(b)?(a):(b)) using namespace std;//求最大公约数int gcd(int x, int y){int big = max(x,y);int small = min(x,y);while (small != 0){int temp = big % small;big = small;small = temp;}return big;}int main(){ifstream fin("fence9.in");ofstream fout("fence9.out");int n, m, p;fin >> n >> m >> p;if (m == 0){fout << 0 << endl;return 0;}int b = gcd(n,m) + p + gcd(max(n,p)-min(n,p), m);int s = p * m;int result = s/2 + 1 - b/2;fout << result << endl;return 0;}

     运行结果：

Executing... Test 1: TEST OK [0.022 secs, 3012 KB] Test 2: TEST OK [0.000 secs, 3012 KB] Test 3: TEST OK [0.011 secs, 3012 KB] Test 4: TEST OK [0.032 secs, 3012 KB] Test 5: TEST OK [0.000 secs, 3012 KB] Test 6: TEST OK [0.011 secs, 3012 KB] Test 7: TEST OK [0.000 secs, 3012 KB] Test 8: TEST OK [0.000 secs, 3012 KB] Test 9: TEST OK [0.000 secs, 3012 KB] Test 10: TEST OK [0.000 secs, 3012 KB] Test 11: TEST OK [0.011 secs, 3012 KB] Test 12: TEST OK [0.011 secs, 3012 KB]All tests OK.

    宏定义是把双刃剑，是减少了代码量，但是遇到麻烦时，调试也更加的难了。