UVa 327 Evaluating Simple C Expressions

/*
coder: ACboy
date: 2010-3-14
result: 1A
description: UVa 327 Evaluating Simple C Expressions
*/
#include <iostream>
#include <algorithm>
using namespace std;
struct Node {
char name;
int value;
int lastValue;
int pos;
};
int cmp(const Node & a, const Node & b)
{
return a.name < b.name;
}
Node data[30];
int vis[256];
int main()
{
char input[256];
char temp[256];
char Temp[256];
#ifndef ONLINE_JUDGE
freopen("327.txt", "r", stdin);
#endif
while (gets(input))
{
int i, j;
int c = 0;
int count = 0;
int len = strlen(input);
for (i = 0; i < len; i++)
{
if (input[i] != ' ') {
temp[c++] = input[i];
if (isalpha(input[i])) {
data[count].name = input[i];
data[count].value = input[i] - 'a' + 1;
data[count].lastValue = data[count].value;
data[count].pos = c - 1;
count++;
}
}
temp[c] = '\0';
}

memset(vis, 0, sizeof(vis));
for (i = 0; i < count; ++i) {
int pos = data[i].pos;
if (pos - 2 >= 0) {
if (temp[pos - 1] == temp[pos - 2] && temp[pos - 1] == '-') {
data[i].value--;
data[i].lastValue = data[i].value;
vis[pos - 1] = 1;
vis[pos - 2] = 1;
}

if (temp[pos - 1] == temp[pos - 2] && temp[pos - 1] == '+') {
data[i].value++;
data[i].lastValue = data[i].value;
vis[pos - 1] = 1;
vis[pos - 2] = 1;
}
}

if (pos + 2 < len) {
if (temp[pos + 1] == temp[pos + 2] && temp[pos + 1] == '-') {
data[i].lastValue = data[i].value - 1;
vis[pos + 1] = vis[pos + 2] = 1;
}

if (temp[pos + 1] == temp[pos + 2] && temp[pos + 1] == '+') {
data[i].lastValue = data[i].value + 1;
vis[pos + 1] = vis[pos + 2] = 1;
}
}
}
c = 0;
for (i = 0; i < len; ++i)
{
if (!vis[i]) {
Temp[c++] = temp[i];
}
}
Temp[c] = '\0';
len = strlen(Temp);