c - OpenMP 循环上的段错误(核心转储)

Question

我有一个算法，可以在另一个字符串中查找一个字符串，并且我得到了一些很长的字符串:

Segmentation fault (core dumped)

这是我的代码，其中:S是要查找的字符串，B是可能包含S字符串的大字符串

int search( char *S, int sizeS, char *B, int sizeB )
{
    int result = -1;

    #pragma omp parallel shared(result)
    {
        int startB, thread, threads, length;

        threads = omp_get_num_threads();
        thread = omp_get_thread_num();

        length = sizeB / threads;

        for(startB = length * thread; result==-1 && startB <= startB+length; startB++ ) {
            int ind;

            for( ind = 0; ind < sizeS; ind++ ) {
                if ( S[ind] != B[startB+ind] )  break;
            }

            if ( ind == sizeS && result == -1)
                result = startB;
        }
    }
    return result;
}

Answer 1

我在您的代码中发现了两个拼写错误:

错误的for循环条件(导致崩溃):

for(startB = length * thread; result==-1 && startB <= startB ; startB++ ) 

应该是:

for(startB = length * thread; result==-1 && startB <= sizeB ; startB++ ) 

然后，ind 测试似乎是错误的(这会阻止找到子字符串):

if ( ind == sizeS && result == -1)
    result = startB;

应该是

if ( ind == (sizeS - 1) && result == -1)
    result = startB;