趣味算法-括号匹配

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

// using stack to save and judge the string
// return the index where the bracket not match
// return 0 no problem
int IsMatch(char* strTest, int nLen)
{
char* pStack = NULL;
char* pChr = strTest;
int   i = 0;
int   nStackIdx = 0;

if ((pChr == NULL) || (nLen == 0))
{
return -1;
}
pStack = (char*) malloc(sizeof(char)*nLen);

if (pStack == NULL)
{
return -1;
}

while (i < nLen)
{
switch(*pChr)
{
case '{':
case '[':
case '(':
case '<':
pStack[nStackIdx] = *pChr;
nStackIdx++;
break;

case '}':
if ((nStackIdx > 0) && (pStack[nStackIdx-1] == '{'))
{
nStackIdx--;
}
else
{
printf("Miss mathc } at %d\n", i+1);
return i+1;
}
break;
case ']':
if ((nStackIdx > 0) && (pStack[nStackIdx-1] == '['))
{
nStackIdx--;
}
else
{
printf("Miss mathc ] at %d\n", i+1);
return i+1;
}
break;
case ')':
if ((nStackIdx > 0) && (pStack[nStackIdx-1] == '('))
{
nStackIdx--;
}
else
{
printf("Miss match ) at %d\n", i+1);
return i;
}
break;
case '>':
if ((nStackIdx > 0) && (pStack[nStackIdx-1] == '<'))
{
nStackIdx--;
}
else
{
printf("Miss match > at %d\n", i+1);
return i;
}
break;
default:
break;
}
i++;
pChr++;
}
if (nStackIdx == 0)
printf("The string: %s is ok\n", strTest);
else
printf("The string is not bracket match: missing %c at %d\n",
pStack[nStackIdx-1], nStackIdx);

free(pStack);
return nStackIdx;
}

int main()
{
char sTestOk[] = "{<[<<{{{[<<>>[[]]]}}}>>]>}";
char sTestFail[] = "{";
char sTestFail1[] = "<<{[(asdfe]]}>>";
int i = 0;
IsMatch(sTestOk, strlen(sTestOk));
IsMatch(sTestFail, strlen(sTestFail));
IsMatch(sTestFail1, strlen(sTestFail1));
scanf("%d", &i);
return 0;
}