UVa 1641 ASCII Area (计算几何，水题)

题意：给定一个矩阵，里面有一个多边形，求多边形的面积。

析：因为是在格子里，并且这个多边形是很规则的，所以所有格子不是全属于多边形就是全不属于，或者一半，并且我们可以根据"/"和“”的数目来知道，如果是奇数，那么就是属于，

偶数就是不属于。

代码如下：

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <cstdio>
#include <string>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <cstring>
#include <set>
#include <queue>
#include <algorithm>
#include <vector>
#include <map>
#include <cctype>
#include <cmath>
#include <stack>
#define frer freopen("in.txt", "r", stdin)
#define frew freopen("out.txt", "w", stdout)
using namespace std;

typedef long long LL;
typedef pair<int, int> P;
const int INF = 0x3f3f3f3f;
const double inf = 0x3f3f3f3f3f3f;
const double PI = acos(-1.0);
const double eps = 1e-8;
const int maxn = 1e2 + 5;
const int mod = 1e9 + 7;
const char *mark = "+-*";
const int dr[] = {-1, 0, 1, 0};
const int dc[] = {0, 1, 0, -1};
const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};
int n, m;
const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
inline int Min(int a, int b){ return a < b ? a : b; }
inline int Max(int a, int b){ return a > b ? a : b; }
inline LL Min(LL a, LL b){ return a < b ? a : b; }
inline LL Max(LL a, LL b){ return a > b ? a : b; }
inline bool is_in(int r, int c){
    return r >= 0 && r < n && c >= 0 && c < m;
}
char s[maxn];

int main(){
    while(scanf("%d %d", &n, &m) == 2){
        int ans = 0;
        for(int i = 0; i < n; ++i){
            int cnt = 0;
            scanf("%s", s);
            for(int j = 0; j < m; ++j){
                if(s[j] == '/' || s[j] == '\')  ++ans, ++cnt;
                else if(cnt & 1)  ans += 2;
            }
        }
        printf("%d
", ans/2);
    }
    return 0;
}