数据结构实验之串三：KMP应用

Problem Description

有n个小朋友，每个小朋友手里有一些糖块，现在这些小朋友排成一排，编号是由1到n。现在给出m个数，能不能唯一的确定一对值l和r(l <= r)，使得这m个数刚好是第l个小朋友到第r个小朋友手里的糖块数？

Input

首先输入一个整数n，代表有n个小朋友。下一行输入n个数，分别代表每个小朋友手里糖的数量。
之后再输入一个整数m，代表下面有m个数。下一行输入这m个数。

Output

 如果能唯一的确定一对l,r的值，那么输出这两个值，否则输出-1

Example Input

5
1 2 3 4 5
3
2 3 4

Example Output

2 4

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define MAXSTRLEN 1000005
#define OVERFLOW -2
#define ERROR -1
#define OK 1

typedef int CElemtype;
typedef int Statu;
typedef struct
{
CElemtype *ch;
int length;
} Hstring;
int next[MAXSTRLEN];
int n, m;
int sum = 0;

Statu InitString(Hstring &T);  //初始化串
Statu StrAssign(Hstring &T, CElemtype str[]); //输入串
Statu StrAssign2(Hstring &T, CElemtype str[]); //输入串
Statu Getnext(int s[]);
Statu Kmp(Hstring T1, Hstring T2, int t);
int main()
{
int i, k;
int s1[MAXSTRLEN], s2[MAXSTRLEN];
Hstring T1, T2;
scanf("%d", &n);
for(i = 0; i < n; i++)
scanf("%d", &s1[i]);
scanf("%d", &m);
for(i = 0; i < m; i++)
scanf("%d", &s2[i]);
InitString(T1);
InitString(T2);
StrAssign(T1, s1);
StrAssign2(T2, s2);
Getnext(s2);
k = Kmp(T1, T2, 0);
if(k > 0)
{
int t = Kmp(T1, T2, k);
if(t > 0)
printf("-1\n");
else
printf("%d %d\n", k, k + T2.length - 1);
}
else
printf("-1\n");
return 0;
}
Statu InitString(Hstring &T)  //初始化串
{
T.ch = (CElemtype *)malloc(MAXSTRLEN*sizeof(CElemtype));
if(!T.ch) exit(0);
T.length = 0;
return OK;
}
Statu StrAssign(Hstring &T, CElemtype str[]) //输入串
{
int i;
for(i = 0; i < n; i++)
{
T.ch[i] = str[i];
T.length++;
}
return OK;
}
Statu StrAssign2(Hstring &T, CElemtype str[]) //输入串
{
int i;
for(i = 0; i < m; i++)
{
T.ch[i] = str[i];
T.length++;
}
return OK;
}
Statu Getnext(int s[])
{
int i = 0, j = -1;
next[0] = -1;
while(i < m)
{
if(j == -1 || s[i] == s[j])
{
i++;
j++;
next[i] = j;
}
else
j = next[j];
}
return OK;
}
Statu Kmp(Hstring T1, Hstring T2, int t)
{
int i = t, j = 0;
while(i < T1.length && j < T2.length)
{
if(j == -1 || T1.ch[i] == T2.ch[j])
{
i++;
j++;
}
else
j = next[j];
}
if(j >= T2.length)
return i - m + 1;
else
return ERROR;
}