写一个c语言程序，设计顺序串的基本运算程序，并用相关数据进行测试

好的，以下是一个基本的顺序串运算程序的C语言代码：

#include <stdio.h>
#include <string.h>

#define MAXLEN 100

typedef struct {
    char data[MAXLEN];
    int length;
} SeqString;

void InitString(SeqString *s, char *str) {
    int len = strlen(str);
    if (len > MAXLEN) {
        printf("String too long!\n");
        return;
    }
    strcpy(s->data, str);
    s->length = len;
}

void PrintString(SeqString s) {
    for (int i = 0; i < s.length; i++) {
        printf("%c", s.data[i]);
    }
    printf("\n");
}

void Concat(SeqString *s1, SeqString s2) {
    if (s1->length + s2.length > MAXLEN) {
        printf("String too long!\n");
        return;
    }
    for (int i = 0; i < s2.length; i++) {
        s1->data[s1->length + i] = s2.data[i];
    }
    s1->length += s2.length;
}

int SubString(SeqString s, int pos, int len, SeqString *sub) {
    if (pos < 1 || pos > s.length || len < 0 || pos + len - 1 > s.length) {
        printf("Invalid position or length!\n");
        return 0;
    }
    for (int i = 0; i < len; i++) {
        sub->data[i] = s.data[pos + i - 1];
    }
    sub->length = len;
    return 1;
}

int Index(SeqString s, SeqString t) {
    int i = 1, j = 1;
    while (i <= s.length && j <= t.length) {
        if (s.data[i - 1] == t.data[j - 1]) {
            i++;
            j++;
        } else {
            i = i - j + 2;
            j = 1;
        }
    }
    if (j > t.length) {
        return i - t.length;
    } else {
        return 0;
    }
}

int main() {
    SeqString s1, s2, sub;
    char str1[] = "Hello";
    char str2[] = "World";
    InitString(&s1, str1);
    InitString(&s2, str2);
    printf("s1: ");
    PrintString(s1);
    printf("s2: ");
    PrintString(s2);
    Concat(&s1, s2);
    printf("s1 after concatenation: ");
    PrintString(s1);
    SubString(s1, 3, 4, &sub);
    printf("Substring of s1 from position 3 with length 4: ");
    PrintString(sub);
    char str3[] = "lo";
    SeqString t;
    InitString(&t, str3);
    int pos = Index(s1, t);
    if (pos) {
        printf("Substring \"%s\" found in s1 at position %d.\n", str3, pos);
    } else {
        printf("Substring \"%s\" not found in s1.\n", str3);
    }
    return 0;
}

你可以用任何你想要的字符串来测试这个程序。