uva 585(字符串)

来源：互联网发布：游戏破解编程编辑：程序博客网时间：2024/06/09 16:49

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;}

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