Problème en mémoire avec des tableaux
Bonjour,
J'ai le programme suivant (implémentation d'un stack) :
Code:
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| #include <stdlib.h>
#include <iostream>
#include <string>
using namespace std;
int nb = 0; // number of elements
int k = 2; // maximum number of elements
int *table; // point to the main table
// init hte stack
void init()
{
table = new int[2];
k=2;
nb = 0;
}
// take an element
int pop()
{
// if stack is empty
if (nb == 0) {
cout << "stack is empty" << endl;
return -1;
}
nb--;
return table[nb];
}
// write an element in the stack
void push(int element)
{
// if the table can't accept the new element
if ((nb + 1) > k) {
int *p; // new pointer for the new table
k = 2 * k;
p = new int[k];
// copy the content to the new table
int i;
for (i = 0; i < nb; i++) {
p[i] = table[i];
}
// delete the old table
delete[] table;
// change the pointer
table = p;
}
// write the element
table[nb] = element;
nb++;
}
// return the size of the stack
int size()
{
return nb;
}
// kill the table in memory
void clear()
{
delete[] table;
nb=0;
}
// test function
int test()
{
cout << "The program has been startet without any arguments." << endl;
cout << "The program enters the stack test mode:" << endl;
cout << "Enter one of the commands: push, pop, end" << endl;
string command;
do {
cin >> command;
if (command == "pop") {
cout << pop() << endl;
} else if (command == "push") {
cout << "element?";
int elementToPush;
cin >> elementToPush;
push(elementToPush);
} else if (command == "end") {
clear();
} else {
cout << "command not recognised" << endl;
};
}
while (command != "end");
return 0;
}
int main(int argc, char *argv[])
{
init();
test();
clear();
return 0;
} |
J'obtiens le résultat suivant (qui est correct) masi avec un message d'erreur :
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| The program has been startet without any arguments.
The program enters the stack test mode:
Enter one of the commands: push, pop, end
push
element?4
push
element?1
pop
1
push
element?5
push
element?9
pop
9
pop
5
pop
4
pop
stack is empty
-1
end
*** glibc detected *** ./array: double free or corruption (fasttop): 0x0804b008 ***
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6[0xb7d2dd65]
/lib/tls/i686/cmov/libc.so.6(cfree+0x90)[0xb7d31800]
/usr/lib/libstdc++.so.6(_ZdlPv+0x21)[0xb7ef6d81]
/usr/lib/libstdc++.so.6(_ZdaPv+0x1d)[0xb7ef6ddd]
./array(__gxx_personality_v0+0x1ae)[0x8048a32]
./array[0x8048cf4]
/lib/tls/i686/cmov/libc.so.6(__libc_start_main+0xe0)[0xb7cda050]
./array(__gxx_personality_v0+0x4d)[0x80488d1]
======= Memory map: ========
08048000-0804a000 r-xp 00000000 08:03 1126215 /home/tguillod/eth/info/ubung/u6/array
0804a000-0804b000 rw-p 00001000 08:03 1126215 /home/tguillod/eth/info/ubung/u6/array
0804b000-0806c000 rw-p 0804b000 00:00 0 [heap]
b7b00000-b7b21000 rw-p b7b00000 00:00 0
b7b21000-b7c00000 ---p b7b21000 00:00 0
b7cc3000-b7cc4000 rw-p b7cc3000 00:00 0
b7cc4000-b7e08000 r-xp 00000000 08:03 476707 /lib/tls/i686/cmov/libc-2.6.1.so
b7e08000-b7e09000 r--p 00143000 08:03 476707 /lib/tls/i686/cmov/libc-2.6.1.so
b7e09000-b7e0b000 rw-p 00144000 08:03 476707 /lib/tls/i686/cmov/libc-2.6.1.so
b7e0b000-b7e0e000 rw-p b7e0b000 00:00 0
b7e0e000-b7e18000 r-xp 00000000 08:03 473347 /lib/libgcc_s.so.1
b7e18000-b7e19000 rw-p 0000a000 08:03 473347 /lib/libgcc_s.so.1
b7e19000-b7e1a000 rw-p b7e19000 00:00 0
b7e1a000-b7e3d000 r-xp 00000000 08:03 476715 /lib/tls/i686/cmov/libm-2.6.1.so
b7e3d000-b7e3f000 rw-p 00023000 08:03 476715 /lib/tls/i686/cmov/libm-2.6.1.so
b7e3f000-b7f27000 r-xp 00000000 08:03 230797 /usr/lib/libstdc++.so.6.0.9
b7f27000-b7f2a000 r--p 000e8000 08:03 230797 /usr/lib/libstdc++.so.6.0.9
b7f2a000-b7f2c000 rw-p 000eb000 08:03 230797 /usr/lib/libstdc++.so.6.0.9
b7f2c000-b7f32000 rw-p b7f2c000 00:00 0
b7f47000-b7f4b000 rw-p b7f47000 00:00 0
b7f4b000-b7f65000 r-xp 00000000 08:03 473300 /lib/ld-2.6.1.so
b7f65000-b7f67000 rw-p 00019000 08:03 473300 /lib/ld-2.6.1.so
bfc3c000-bfc52000 rw-p bfc3c000 00:00 0 [stack]
ffffe000-fffff000 r-xp 00000000 00:00 0 [vdso]
Aborted (core dumped) |
C'est un problème de libération de mémoire (fonction clear()). Mais je n'arrive pas le trouver.
Quelqu'un peut il m'aider ?
