贪心 Codeforces Round #304 (Div. 2) B. Soldier and Badges

 1 /*
 2     题意：问最少增加多少值使变成递增序列
 3     贪心：排序后，每一个值改为前一个值+1，有可能a[i-1] = a[i] + 1，所以要 >=
 4 */
 5 #include <cstdio>
 6 #include <cstring>
 7 #include <algorithm>
 8 using namespace std;
 9 
10 typedef long long ll;
11 
12 const int MAXN = 3e3 + 10;
13 const int INF = 0x3f3f3f3f;
14 int a[MAXN];
15 
16 int main(void)        //Codeforces Round #304 (Div. 2) B. Soldier and Badges
17 {
18     int n;
19     while (scanf ("%d", &n) == 1)
20     {
21         for (int i=1; i<=n; ++i)    scanf ("%d", &a[i]);
22         sort (a+1, a+1+n);
23 
24         int tot = 0;    a[0] = 0;
25         for (int i=1; i<=n; ++i)
26         {
27             if (a[i-1] >= a[i])    {tot += (a[i-1] - a[i] + 1); a[i] = a[i-1] + 1;}
28         }
29 
30         printf ("%d\n", tot);
31     }
32 
33     return 0;
34 }
35 
36 /*
37 4
38 1 3 1 4
39 5
40 1 2 3 2 5
41 4
42 4 3 2 2
43 */