Insertion Sort

http://codeforces.com/problemset/problem/362/C

 1 #include <stdio.h>
 2 #include <string.h>
 3 #include <algorithm>
 4 using namespace std;
 5 const int maxn = 5000 + 5;
 6 const int INF = 1<<30;
 7 int a[maxn], sum[maxn][maxn], sum2[maxn][maxn];
 8 int main() {
 9     int n;
10     scanf("%d", &n);
11     for(int i = 0;i < n; i++) 
12         scanf("%d", &a[i]);
13     for(int i = 0;i < n; i++) {
14         sum[i][i] = 0;
15         for(int j = i+1;j < n; j++) {
16             sum[i][j] = sum[i][j-1];
17             if(a[j] < a[i])
18                 sum[i][j]++;
19         }
20         sum2[i][i] = 0;
21         for(int j = i-1;j >= 0; j--) {
22             sum2[i][j] = sum2[i][j+1];
23             if(a[i] > a[j])
24                 sum2[i][j]++;
25         }
26     }
27     int tot = 0;
28     for(int i = 0;i < n; i++) {
29         for(int j = i+1;j < n; j++) if(a[i] > a[j])
30             tot++;
31     }
32     int mn = INF, ans = 0;
33     for(int i = 0;i < n; i++) {
34         for(int j = i+1;j < n; j++) {
35             int cur = tot + (j-i) - 2*sum[i][j-1] + 2*sum2[j][i+1] - (j-i);
36             if(a[i] > a[j]) cur--;
37             else    cur++;
38             if(cur < mn) {
39                 mn = cur; ans = 1;
40             }
41             else if(cur == mn)  ans++;
42         }
43     }
44     printf("%d %d\n", mn, ans);
45     return 0;
46 }
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posted @ 2016-07-22 19:34  Crazy、baby  阅读(180)  评论(0)  编辑  收藏  举报