贪心/POJ 3617 Best Cow Line

 1 #include<cstdio>
 2 #include<cstring>
 3 using namespace std;
 4 int main()
 5 {
 6     int n;
 7     char s1[2020],s2[2020];
 8     scanf("%d",&n);
 9     for (int i=0;i<n;i++)
10     {
11         char ch;
12         scanf(" %c",&ch);
13         s1[i]=ch;
14     }
15     int l=0,r=n-1,p=0;
16     while (l<=r)
17     {
18         bool left=false;
19         for (int i=0;l+i<=r;i++)
20         {
21             if (s1[l+i]<s1[r-i])
22             {
23                 left=true;
24                 break;
25             }else if (s1[l+i]>s1[r-i])
26             {
27                 left=false;
28                 break;
29             }
30         }
31         if (left) s2[p]=s1[l++];
32         else s2[p]=s1[r--];
33         p++;
34     }
35     for (int i=0;i<n;i++)
36     {
37         printf("%c",s2[i]);
38         if ((i+1)%80==0) printf("\n");
39     }
40     printf("\n");
41     return 0;
42 }