poj2056

寻找向左凸的地方，每个左凸能让S数量-2。上边或下边如果是半个左凸的话则各对应-1

#include <cstdio>
#include <cstring>
#include <cstdlib>
using namespace std;

#define MAX_ROW 205
#define MAX_COLUMN MAX_ROW

int row, column;
char grid[MAX_ROW][MAX_COLUMN];

void input()
{
    memset(grid, 0, sizeof(grid));
    for (int i = 0; i < row; i++)
        scanf("%s", grid[i]);
}

void work()
{
    int direction = -1;    //1 is right, 0 is left
    int s_cnt = 0;
    int x = 0;
    int y = 0;
    while (grid[x][y] != 'S')
        y++;
    s_cnt++;
    while (x < row)
    {
        if (y != 0 && grid[x][y - 1] == 'S')
        {
            direction = 0;
            while (y > 0 && grid[x][y - 1] == 'S')
                y--, s_cnt++;
            x++, s_cnt++;
            continue;
        }
        if (y + 1 < column && grid[x][y + 1] == 'S')
        {
            if (direction == -1)
                s_cnt--;
            if (direction == 0)
                s_cnt -= 2;
            direction = 1;
            while (y + 1 < column && grid[x][y + 1] == 'S')
                y++, s_cnt++;
            x++, s_cnt++;
            continue;
        }
        x++, s_cnt++;
    }
    if (direction == 0)
        s_cnt--;
    printf("%d
", s_cnt - 1);
}

int main()
{
    while (scanf("%d%d", &row, &column), row | column)
    {
        input();
        work();
    }
    return 0;
}