Gym 100090M Jumping along the Hummocks

 1 #include <bits/stdc++.h>
 2 
 3 using namespace std;
 4 
 5 
 6 const int inf = 0x3f3f3f3f;
 7 int a[200005];
 8 int dp[200005];
 9 
10 int main() {
11 
12     int n;
13     while(~scanf("%d",&n)) {
14         for(int i=0;i<n;i++) {
15             scanf("%d",&a[i]);
16         }
17 
18         memset(dp,inf,sizeof(dp));
19         dp[0] = 0;
20         map<int,int> maps;
21         maps[a[0]] = 0;
22         for(int i=1;i<n;i++) {
23             dp[i] = dp[i-1] + 1;
24             if(maps.count(a[i])>0) {
25                 dp[i] = min(dp[i],maps[a[i]] + 1);
26                 maps[a[i]] = dp[i];
27             }
28             else {
29                 maps[a[i]] = dp[i];
30             }
31         }
32         printf("%d\n",dp[n-1]);
33 
34     }
35 
36     return 0;
37 }