kmp+
原创
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#include <iostream>
using namespace std;
typedef struct
{
char ch[1000];
int length;
} SString;
void get_next(SString T, int next[])
{
int i = 1, j = 0;
next[1] = 0;
cout << "选择next[],请按1;选择nextval，请按2: ";
int F;
cin >> F;
while (i < T.length)
{
if (F == 2)
break;
if (j == 0 || [i] == [j])
{
i++;
j++;
next[i] = j;
}
else
j = next[j];
}
while (i < T.length)
{
if (F == 1)
break;
if (j == 0 || [i] == [j])
{
i++;
j++;
if ([i] != [j])
next[i] = j;
else
next[i] = next[j];
}
else
j = next[j];
}
}
void Index_KMP(SString S, SString T, int pos)
{
int i = pos, j = 1, next[1000];
get_next(T, next);
while (i <= S.length && j <= T.length)
{
if (j == 0 || [i] == [j])
{
i++;
j++;
}
else
j = next[j];
}
if (j > T.length)
cout << "从第" << i - T.length << "处开始匹配" << endl;
else
cout << "模式串与主串不匹配" << endl;
}
int main()
{
Loop:
cout << "__________________________________________" << endl;
cout << "******************************************" << endl;
cout << "__________________________________________" << endl;
cout << endl;
SString S, T;
S.length = 0;
T.length = 0;
loop1:
cout << "输入主串的长度(n>=1): ";
int i, n;
char data;
cin >> n;
S.length = n;
cout << "输入主串元素" << endl;
cout << "输入过程中按0退出本次输入" << endl;
cout << "主串元素：";
for (i = 1; i <= n; i++)
{
cin >> data;
if (data - 97 >= 0)
[i] = data;
else
goto loop1;
}
loop2:
cout << "输入模式串的长度(n>=1)：";
cin >> n;
T.length = n;
cout << "输入模式串元素" << endl;
cout << "输入过程中按0退出本次输入" << endl;
cout << "模式串元素：";
for (i = 1; i <= n; i++)
{
cin >> data;
if (data - 97 >= 0)
[i] = data;
else
goto loop2;
}
int pos;
cout << "输入检索位置(pos>=1)：";
cin >> pos;
Index_KMP(S, T, pos);
cout << "继续检索请按1；退出检索请按0" << endl;
int F;
cin >> F;
if (F)
goto Loop;
else
cout << "\t\t谢谢使用" << endl;
cout << "------------------------------------------" << endl;
return 0;
}
