Page 96 - DCAP605_ADVANCED_DATA_STRUCTURE_AND_ALGORITHMS

Unit 4: Queues

Notes
* performs processing of op.
*/
switch(op) {
case ‘)’:
printf( “\t S pushing )...\n” );
sPush( s, op );
break;
case ‘(‘:
while( !qEmpty(q) ) {
*tptr++ = qPop(q);
printf( “\tQ popping %c...\n”, *(tptr-1) );
}
while( !sEmpty(s) ) {
char popop = sPop(s);
printf( “\tS popping %c...\n”, popop );
if( popop == ‘)’ )
break;
*tptr++ = popop;
}
break;
default: {
int priop; // priority of op.
char topop; // operator on stack top.
int pritop; // priority of topop.
char asstop; // associativity of topop.
while( !sEmpty(s) ) {
priop = getPriority(op);
topop = sTop(s);
pritop = getPriority(topop);
asstop = getAssociativity(topop);
if( pritop < priop || (pritop == priop && asstop == ‘L’)
|| topop == ‘)’ ) // IMP.
break;
while( !qEmpty(q) ) {
*tptr++ = qPop(q);
printf( “\tQ popping %c...\n”, *(tptr-1) );
}
*tptr++ = sPop(s);
printf( “\tS popping %c...\n”, *(tptr-1) );
Contd...

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