Time Limit: 20 Sec
Memory Limit: 256 MB
题目连接
http://codeforces.com/problemset/problem/368/B
Description
Sereja wrote out the necessary array elements but the array was so large and the boy was so pressed for time. Help him, find the answer for the described question for each li.
Input
The first line contains two integers n and m (1 ≤ n, m ≤ 105). The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 105) — the array elements.
Next m lines contain integers l1, l2, ..., lm. The i-th line contains integer li (1 ≤ li ≤ n).
Output
Print m lines — on the i-th line print the answer to the number li.
Sample Input
10 10
1 2 3 4 1 2 3 4 100000 99999
1
2
3
4
5
6
7
8
9
10
Sample Output
6
6
6
6
6
5
4
3
2
1
HINT
题意
n个数,m次询问
每次询问,问你[l,n]有多少不同的数字
题解:
用map就好了
我们离线做
代码
#include <cstdio> #include <cmath> #include <cstring> #include <ctime> #include <iostream> #include <algorithm> #include <set> #include <vector> #include <sstream> #include <queue> #include <typeinfo> #include <fstream> #include <map> #include <stack> typedef long long ll; using namespace std; //freopen("D.in","r",stdin); //freopen("D.out","w",stdout); #define sspeed ios_base::sync_with_stdio(0);cin.tie(0) #define test freopen("test.txt","r",stdin) #define maxn 1050005 #define mod 10007 #define eps 1e-9 const int inf=0x3f3f3f3f; const ll infll = 0x3f3f3f3f3f3f3f3fLL; inline ll read() { ll x=0,f=1;char ch=getchar(); while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();} while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();} return x*f; } //************************************************************************************** int ans[maxn]; int a[maxn]; map<int,int> H; int flag=0; int main() { int n=read(),m=read(); for(int i=1;i<=n;i++) { a[i]=read(); H[a[i]]++; if(H[a[i]]==1) flag++; } for(int i=1;i<=n;i++) { ans[i]=flag; H[a[i]]--; if(H[a[i]]==0) flag--; } for(int i=1;i<=m;i++) { int x=read(); printf("%d\n",ans[x]); } }