Why and I getting a infinate loop with a user uses test input such as " 133 x"

My Code works for all test cases below, but if you test it with input and use a non numerical value as the last input it goes into a endless loop. Please help!!

I believe my error is with this part of the loop:

while(true){

cout

cin >> buf;

if(buf[0] == 'q' || buf[0] == 'Q')

break;

cin >> val;

input = atoi(buf);

if(input >= 0 && input

a[input] = val;

b[input] = 1;

}

} // While Close

Here is my code:

#include

using namespace std;

#include

#include

#include

class Array

{

private:

int values[100];

int dummy;

public:

Array();

int operator[](int) const;

int& operator[](int);

int capacity() const;

}; // Array class

Array::Array()

{

dummy = 0;

for(int i = 0; i

values[i] = 0;

} // constructor

int Array::operator[](int index) const

{

if(index = 100)

return 0;

return values[index];

} // getter

int& Array::operator[](int index)

{

if(index = 100)

return dummy;

return values[index];

} // setter

int Array::capacity() const

{

return 100;

} // capacity

int main()

{

//Delclarations

Array a;

Array b;

int input, val;

int count = 0;

char buf[10];

// Read user input for index and value

while(true){

cout

cin >> buf;

if(buf[0] == 'q' || buf[0] == 'Q')

break;

cin >> val;

input = atoi(buf);

if(input >= 0 && input

a[input] = val;

b[input] = 1;

}

} // While Close

for(int i = 0; i

if(b[i] == 1)

count += 1;

} // For Close

// Output

cout

cout

cout

for(int i = 0; i

if(b[i] != 0)

cout "

} // For Close

cout

// Read user input for look up values

while(true){

cout

cin >> buf;

if(buf[0] == 'q' || buf[0] == 'Q')

break;

input = atoi(buf);

if(b[input] != 0){

cout

cout

} // if

else

cout

} // While Close

} // Close Main

Here's a sample of how this should work (user input in blue) Input an index and a value [Q to quit]: 33 12 Input an index and a value [Q to quit]: 4 100 Input an index and a value [Q to quit]: 5 300 Input an index and a value [Q to quit]: x 17 Input an index and a value [Q to quit]: 33 120 Input an index and a value [Q to quit]: -1 23.4 Input an index and a value [Q to quit]: 2000 -999 Input an index and a value [Q to quit]: q You stored this many values: 4 The index-value pairs are: 0 => 17 4 => 100 5 => 300 33 => 120 Input an index for me to look up [Q to quit]: 33 Found it -- the value stored at 33 is 120 Input an index for me to look up [Q to quit]: 38 I didn't find it Input an index for me to look up [Q to quit]: 0 Found it -- the value stored at0 is 1.7 Input an index for me to look up [Q to quit]: -100 I didn't find it Input an index for me to look up [Q to quit]: 1000 I didn't find it Input an index for me to look up [Q to quit]