http://acm.hdu.edu.cn/showproblem.php?pid=1711
Number Sequence
Time Limit: 10000/5000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 30591 Accepted Submission(s): 12870
Problem Description
Given
two sequences of numbers : a[1], a[2], ...... , a[N], and b[1], b[2],
...... , b[M] (1 <= M <= 10000, 1 <= N <= 1000000). Your
task is to find a number K which make a[K] = b[1], a[K + 1] = b[2],
...... , a[K + M - 1] = b[M]. If there are more than one K exist, output
the smallest one.
Input
The
first line of input is a number T which indicate the number of cases.
Each case contains three lines. The first line is two numbers N and M (1
<= M <= 10000, 1 <= N <= 1000000). The second line contains
N integers which indicate a[1], a[2], ...... , a[N]. The third line
contains M integers which indicate b[1], b[2], ...... , b[M]. All
integers are in the range of [-1000000, 1000000].
Output
For each test case, you should output one line which only contain K described above. If no such K exists, output -1 instead.
Sample Input
2
13 5
1 2 1 2 3 1 2 3 1 3 2 1 2
1 2 3 1 3
13 5
1 2 1 2 3 1 2 3 1 3 2 1 2
1 2 3 2 1
Sample Output
6
-1
Source
把数字离散化后当作字符来处理就是kmp了,注意模板是从下标0开始的我一直输入时从1开始导至答案不对。
1 #include<cstring> 2 #include<cstdio> 3 #include<map> 4 #include<iostream> 5 using namespace std; 6 map<int,int>M; 7 int nex[10005],l1,l2,sl; 8 int S[1000005],T[10005]; 9 int solve() 10 { 11 int i,j; 12 nex[0]=nex[1]=0; 13 for(i=1;i<l2;++i) 14 { 15 j=nex[i]; 16 while(j&&T[i]!=T[j])j=nex[j]; 17 nex[i+1]=T[i]==T[j]?j+1:0; 18 } 19 j=0; 20 for(i=0;i<l1;++i) 21 { 22 while(j&&S[i]!=T[j])j=nex[j]; 23 if(S[i]==T[j]){ 24 j++; 25 if(j==l2)return i-l2+2; 26 } 27 } 28 return -1; 29 } 30 int main() 31 { 32 int i,j,t,p,x,tmp; 33 cin>>t; 34 while(t--){p=0;M.clear(); 35 scanf("%d%d",&l1,&l2); 36 for(i=0;i<l1;++i) 37 { 38 scanf("%d",&x); 39 tmp=M[x]; 40 if(!tmp){M[x]=S[i]=++p;} 41 else S[i]=tmp; 42 } 43 for(i=0;i<l2;++i) 44 { 45 scanf("%d",&x); 46 tmp=M[x]; 47 if(!tmp){M[x]=T[i]=++p;} 48 else T[i]=tmp; 49 } 50 cout<<solve()<<endl;; 51 } 52 return 0; 53 }