Lightoj 1389-scarecrow (greedy AH)

Title Link: http://lightoj.com/volume_showproblem.php?problem=1389

Taso owns a very long field. He plans to grow different types of crops in the upcoming growing season. The area, however, are full of crows and Taso fears that they might feeds on the most of the crops. For this reason, he had decided to place some scarecrows at different locations of the field.

The field can be modeled as a 1 x N grid. Some parts of the field is infertile and that means you cannot grow all crops on them. A scarecrow, when placed in a spot, covers the cell to its immediate left and right along with the cell it's on.

Given the description of the field, what's the minimum number of scarecrows that needs to being placed so and all the Usefu L section of the field is covered? Useful section refers to cells where crops can is grown.

Input

Input starts with an integer T (≤50), denoting the number of test cases.

Each case is starts with a line containing an integer N (0 < N <). The next line contains N characters that describe the field. A dot (.) indicates a crop-growing spot and a hash (#) indicates a infertile region.

Output

For each case, print the case number and the number of scarecrows that need to be placed.

Sample Input	Output for Sample Input
3 3 .#. 11 ...##....## 2 ##	Case 1:1 Case 2:3 Case 3:0

Test instructions

Each scarecrow can cover his own point and the left and right two points, using a minimum of straw to cover all the points that can be planted ('. ') ）；

The code is as follows:

#include <cstdio> #include <cstring>int main () {    int t;    int n;    Char s[147];    int cas = 0;    scanf ("%d", &t);    while (t--)    {        scanf ("%d", &n);        scanf ("%s", s);        int len = strlen (s);        int ans = 0;        for (int i = 0; i < n; i++)        {            if (s[i] = = ' # ')                continue;            if (s[i] = = '. ')            {                ans++;            }            i + = 2;        }        printf ("Case%d:%d\n", ++cas,ans);    }    return 0;}

Lightoj 1389-scarecrow (greedy AH)