uva 585(字符串)

题意：有个倒三角形如图所示

要求最大的全部是白色小三角形组成的倒三角形的小三角形的数量。输入-表示白色，#表示黑色。

题解：暴力枚举顶点的找最大解，注意每行从0开始计小三角形，编号为偶数的只能往上面找，编号为奇数的只能往下面找。

#include <stdio.h>
#include <string.h>
#include <algorithm>
using namespace std;
const int N = 105;
char s[N][N + N];
int n, res;

void Count(int x, int y, int k) {
	int temp = 1;
	if (k % 2 == 0) {
		int x1 = x, y1 = y, y2 = y;
		while (1) {
			x1--;
			y1--;
			y2++;
			int i;
			if (x1 < 0 || y1 < x1 || y2 >= 2 * n - x1 - 1)
				break;
			for (i = y1; i <= y2; i++)
				if (s[x1][i] != '-')	
					break;
			if (i != y2 + 1)
				break;
			temp += y2 - y1 + 1;
		}
	}
	else {
		int x1 = x, y1 = y, y2 = y;
		while (1) {
			x1++;
			y1--;
			y2++;
			int i;
			if (x1 >= n || y1 < 0 || y2 >= 2 * n - x1 - 1)
				break;
			for (i = y1; i <= y2; i++)
				if (s[x1][i] != '-')
					break;
			if (i != y2 + 1)
				break;
			temp += y2 - y1 + 1;
		}
	}
	res = max(res, temp);
}

int main() {
	int cas = 1;
	while (scanf("%d", &n) == 1 && n) {
		for (int i = 0; i < n; i++)
			scanf("%s", s[i] + i);
		res = 0;
		for (int i = 0; i < n; i++)
			for (int j = i, k = 0; j < 2 * n - i - 1; j++, k++)
				if (s[i][j] == '-')
					Count(i, j, k);
		printf("Triangle #%d\nThe largest triangle area is %d.\n\n", cas++, res);
	}
	return 0;
}