字符串subscipt超出范围 [英] String subscipt out of range
问题描述
我的代码,在MS VS 2012中编译后,接受输入,因为它应该,然后崩溃与以下报告:
My code, after being compiled in MS VS 2012, accepts input as it should, and then crashes with the following report:
Debug Assertion Failed!
...\include\xstring
Line:1662
Expression:string subscript out of range
代码如下:
#include "stdafx.h"
#include <iostream>
#include <string>
#include <vector>
#include <cassert>
#include <time.h>
using namespace std;
const unsigned short MAX_STRINGS = 10;
const unsigned int MAX_SIZE=10000;
vector<string> strings;
unsigned int len;
string GetLongestCommonSubstring( string string1, string string2 );
inline void readNumberSubstrings();
inline const string getMaxSubstring();
void readNumberSubstrings()
{
cin >> len;
assert(len > 1 && len <=MAX_STRINGS);
strings.resize(len);
for(unsigned int i=0; i<len;i++)
strings[i]=string(MAX_SIZE,0);
for(unsigned int i=0; i<len; i++)
cin>>strings[i];
}
const string getMaxSubstring()
{
string maxSubstring=strings[0];
long T=clock();
for(unsigned int i=1; i < len; i++)
maxSubstring=GetLongestCommonSubstring(maxSubstring, strings[i]);
cout << clock()-T << endl;
return maxSubstring;
}
string GetLongestCommonSubstring( string string1, string string2 )
{
const int solution_size = string2.length()+ 1;
int *x=new int[solution_size]();
int *y= new int[solution_size]();
int **previous = &x;
int **current = &y;
unsigned int max_length = 0;
unsigned int result_index = 0;
unsigned int j;
unsigned int length;
int J=string2.length() - 1;
for(unsigned int i = string1.length() - 1; i >= 0; i--)
{
for(j = J; j >= 0; j--)
{
if(string1[i] != string2[j])
(*current)[j] = 0;
else
{
length = 1 + (*previous)[j + 1];
if (length > max_length)
{
max_length = length;
result_index = i;
}
(*current)[j] = length;
}
}
swap(previous, current);
}
string1[max_length+result_index]='\0';
return &(string1[result_index]);
}
int main()
{
readNumberSubstrings();
cout << getMaxSubstring() << endl;
return 0;
}
我想这肯定是一件很简单的事情
I guess it must be something really simple (like some loop condition or something like that) that causes it to crash, but I fail to see it.
推荐答案
您的问题在于使用 unsigned int
。看看这一行:
Your problem is in using unsigned int
. Look at this line:
for(j = J; j >= 0; j--)
这里,在j变为0之后,它减少。但您的 j
是 unsigned
,因此不是变成 -1
(并在下一次迭代时退出循环), j
变为 4158584613
,并且循环继续,在此行的索引 4158584613
处的明显的外键元素:
Here, after j becomes 0, it gets decremented. But your j
is unsigned
, so instead of becoming -1
(and exiting the cycle on the next iteration), j
becomes 4158584613
, and the cycle continues, trying to access the obviously out-of-bonds element at index 4158584613
at this line:
(*current)[j] = 0;
制作 i
, j
和 length
签名将解决您的问题。
Making i
, j
, and length
signed will solve your problem.
这篇关于字符串subscipt超出范围的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!