Hamburger String |
Time Limit: 1000ms, Special Time Limit:2500ms, Memory Limit:65536KB |
Total submit users: 17, Accepted users: 15 |
Problem 10865 : No special judgement |
Problem description |
BUG is a famous burger shop. Lots of costumers wait for burgers outside the burger every morning, because those hamburgers are so unforgettable.
Costumers stand in a queue, they come one by one, the latest one join into the end. When a costumer(A) come to the end of the queue, if there’s already someone(B), wearing the same color as him, people between them(including A and B, called Hamburger String) will be served. Served people leave the queue immediately. N people come one by one, given their colors, can you tell me how many Hamburger Strings are there? |
Input |
The first line is an integer T(T<=100).
Each case has an integer N(N<=100) in the first line. Then N positive integers(<=20) follow, each corresponds a kind of color. 1 for red, 2 for yellow, and so on. |
Output |
For each case output a single integer, indicating the number of Hamburger Strings are served.
|
Sample Input |
3 1 1 2 2 2 10 1 2 3 4 3 1 2 4 1 5 |
Sample Output |
0 1 2 |
Problem Source |
2011ACM国际大学生程序设计竞赛湘潭邀请赛 |
代码:
#include <iostream>
#include <algorithm>
#include <cstdio>
#define llt long long
using namespace std;
int a[30000];
int ans;
void dfs(int l,int r){
if(l>=r) return ;
for(int i=l+1;i<=r;++i){
if(a[i]==a[l]){
ans++;
dfs(l+1,i-1);
dfs(i+1,r);
return ;
}
}
dfs(l+1,r);
}
int main()
{
int T;
scanf("%d",&T);
while(T--){
int n;
scanf("%d",&n);
for(int i=1;i<=n;++i) scanf("%d",&a[i]);
ans = 0;
dfs(1,n);
printf("%d\n",ans);
}
return 0;
}