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

题目传送门

 /*
     题意：问最少增加多少值使变成递增序列
     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 >=
 */
 #include <cstdio>
 #include <cstring>
 #include <algorithm>
 using namespace std;

 typedef long long ll;

 const int MAXN = 3e3 + ;
 const int INF = 0x3f3f3f3f;
 int a[MAXN];

 int main(void)        //Codeforces Round #304 (Div. 2) B. Soldier and Badges
 {
     int n;
     while (scanf ("%d", &n) == )
     {
         for (int i=; i<=n; ++i)    scanf ("%d", &a[i]);
         sort (a+, a++n);

         int tot = ;    a[] = ;
         for (int i=; i<=n; ++i)
         {
             if (a[i-] >= a[i])    {tot += (a[i-] - a[i] + ); a[i] = a[i-] + ;}
         }

         printf ("%d\n", tot);
     }

     return ;
 }

 /*
 4
 1 3 1 4
 5
 1 2 3 2 5
 4
 4 3 2 2
 */