strtok未处理的exception;访问冲突写入位置

#include  #include  #include  char *matrix[10][10]; int main(void) { int i; char *list[4]; char *words[20] = { " cat ", " car ", " bear ", " ship ", " mouse ", " beatle ", " coat ", " nest ", " ice ", " sugar ", " bacon ", " frown ", " smile ", " dead ", " feather ", " goat ", " hen "," jelly "," koala "," lips " }; int length; int num; int k; int m; char otherString=0; char *c; int j; int s; int r; char test[10]; char *token; const char *search = " "; char *empty = ""; int size; int ans; int x; int y; int pos; int pos2; int randRow; int randColumn; int chosen[10]; int random; int d; int ROWS = 10; // number of rows int COLUMNS = 10; // number of columns printf("\tA\tB\tC\tD\tE\tF\tG\tH\tI\tJ\n"); srand(time(NULL)); for (i = 0; i < 4; i++) { printf( "\n" ); d = 0; do { random = (rand() % 20); list[i] = words[random]; d = 0; for (j = 0; j < i; j++) { if (strcmp(words[random], list[j]) == 0) d = 1; } } while (d); } token = strtok((words[random]), search); while (token != NULL) { length = strlen(words[random]); for (k = 0; k < length; k++) { matrix[i][k] = token; token = strtok(NULL, search); matrix [i][k] = token; } } for (r = 0; r < 10; r++) { printf("\n"); for (s = 0; s < 10; s++) { //ans = strlen(matrix[r][s]); /* if (ans == 0) { c = 'A' + (rand() % 26); matrix[r][s] = c; }*/ printf("\t%s", matrix[r][s]); } } getchar(); return 0; } 

基本上这个程序生成4个随机单词，不能重复strtok用于滑动单词，以便它们可以通过char输入char到矩阵中。 最后，矩阵中的任何空字符都将被替换为随机字符。 但是strtok正在生成运行时错误，我不知道如何检查null元素？

Answer 1

在这个声明中

 token = strtok((words[random]),search); 

function strtok尝试更改由数组元素words[random]寻址的字符串文字。

字符串文字在C中是不可变的。任何更改字符串文字的尝试都会导致未定义的行为。

而不是指向字符串文字的指针数组

  char *words[20]={" cat "," car "," bear "," ship "," mouse "," beatle "," coat "," nest "," ice "," sugar "," bacon "," frown "," smile "," dead "," feather "," goat "," hen "," jelly "," koala "," lips "}; 

你应该定义一个由字符串文字初始化的二维字符数组。 例如

  char words[20][20]={" cat "," car "," bear "," ship "," mouse "," beatle "," coat "," nest "," ice "," sugar "," bacon "," frown "," smile "," dead "," feather "," goat "," hen "," jelly "," koala "," lips "}; 

Answer 2

  token = strtok((words[random]),search); while(token!=NULL) { length=strlen(words[random]); for( k=0;k 

这是混乱而不是你想要的。 将其改为直线，例如：

  for (k = 0, c = words[random]; token = strtok(c, search); c = NULL, ++k) matrix[i][k] = token;