#include <stdio.h> #include <string.h> void preKMP(char *pattern, int *prefix, int n) { int len = 0; prefix[0] = 0; for (int i = 1; i < n; i++) { while (len > 0 && pattern[i] != pattern[len]) { len = prefix[len - 1]; } if (pattern[i] == pattern[len]) { len++; } prefix[i] = len; } } void KMP(char *text, char *pattern) { int n = strlen(pattern); int m = strlen(text); int *prefix = malloc(n * sizeof(int)); preKMP(pattern, prefix, n); int j = 0; for (int i = 0; i < m; i++) { while (j > 0 && text[i] != pattern[j]) { j = prefix[j - 1]; } if (text[i] == pattern[j]) { j++; } if (j == n) { printf("Pattern found at index %d ", i - j + 1); j = prefix[j - 1]; } } free(prefix); } int main() { char text[100]; char pattern[100]; printf("Enter the text: "); fgets(text, 100, stdin); printf("Enter the pattern: "); fgets(pattern, 100, stdin); KMP(text, pattern); return 0; }找出以上程序错误并修改

在程序中，应该先判断输入的字符串是否包含换行符，如果包含则需要将其替换为字符串结束符'\0'。此外，在使用动态分配内存时，需要在程序结束时及时释放内存。

以下是修改后的程序：

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

void preKMP(char *pattern, int *prefix, int n) {
    int len = 0;
    prefix[0] = 0;
    for (int i = 1; i < n; i++) {
        while (len > 0 && pattern[i] != pattern[len]) {
            len = prefix[len - 1];
        }
        if (pattern[i] == pattern[len]) {
            len++;
        }
        prefix[i] = len;
    }
}

void KMP(char *text, char *pattern) {
    int n = strlen(pattern);
    int m = strlen(text);
    
    int *prefix = malloc(n * sizeof(int));
    preKMP(pattern, prefix, n);
    
    int j = 0;
    for (int i = 0; i < m; i++) {
        while (j > 0 && text[i] != pattern[j]) {
            j = prefix[j - 1];
        }
        if (text[i] == pattern[j]) {
            j++;
        }
        if (j == n) {
            printf("Pattern found at index %d\n", i - j + 1);
            j = prefix[j - 1];
        }
    }
    
    free(prefix);
}

int main() {
    char text[100];
    char pattern[100];
    
    printf("Enter the text: ");
    fgets(text, 100, stdin);
    text[strcspn(text, "\n")] = '\0'; // 替换换行符为'\0'
    
    printf("Enter the pattern: ");
    fgets(pattern, 100, stdin);
    pattern[strcspn(pattern, "\n")] = '\0'; // 替换换行符为'\0'
    
    KMP(text, pattern);
    
    return 0;
}