/*
* recursive sub-function of compactToUnicodeHelper()
* returns:
* >0 number of bytes that are used in unicodeCodeUnits[] that could be saved,
* if all sequences from this state are unassigned, returns the
* <0 there are assignments in unicodeCodeUnits[]
* 0 no use of unicodeCodeUnits[]
*/
static int32_t
findUnassigned(UCMStates *states,
uint16_t *unicodeCodeUnits,
_MBCSToUFallback *toUFallbacks, int32_t countToUFallbacks,
int32_t state, int32_t offset, uint32_t b) {
int32_t i, entry, savings, localSavings, belowSavings;
UBool haveAssigned;
localSavings=belowSavings=0;
haveAssigned=FALSE;
for(i=0; i<256; ++i) {
entry=states->stateTable[state][i];
if(MBCS_ENTRY_IS_TRANSITION(entry)) {
savings=findUnassigned(states,
unicodeCodeUnits,
toUFallbacks, countToUFallbacks,
MBCS_ENTRY_TRANSITION_STATE(entry),
offset+MBCS_ENTRY_TRANSITION_OFFSET(entry),
(b<<8)|(uint32_t)i);
if(savings<0) {
haveAssigned=TRUE;
} else if(savings>0) {
printf(" all-unassigned sequences from prefix 0x%02lx state %ld use %ld bytes\n",
(unsigned long)((b<<8)|i), (long)state, (long)savings);
belowSavings+=savings;
}
} else if(!haveAssigned) {
switch(MBCS_ENTRY_FINAL_ACTION(entry)) {
case MBCS_STATE_VALID_16:
entry=offset+MBCS_ENTRY_FINAL_VALUE_16(entry);
if(unicodeCodeUnits[entry]==0xfffe && ucm_findFallback(toUFallbacks, countToUFallbacks, entry)<0) {
localSavings+=2;
} else {
haveAssigned=TRUE;
}
break;
case MBCS_STATE_VALID_16_PAIR:
entry=offset+MBCS_ENTRY_FINAL_VALUE_16(entry);
if(unicodeCodeUnits[entry]==0xfffe) {
localSavings+=4;
} else {
haveAssigned=TRUE;
}
break;
default:
break;
}
}
}
if(haveAssigned) {
return -1;
} else {
return localSavings+belowSavings;
}
}
/* helper function for finding compaction opportunities */
static void
compactToUnicodeHelper(UCMStates *states,
uint16_t *unicodeCodeUnits,
_MBCSToUFallback *toUFallbacks, int32_t countToUFallbacks) {
int32_t state, savings;
/* for each initial state */
for(state=0; state<states->countStates; ++state) {
if((states->stateFlags[state]&0xf)==MBCS_STATE_FLAG_DIRECT) {
savings=findUnassigned(states,
unicodeCodeUnits,
toUFallbacks, countToUFallbacks,
state, 0, 0);
if(savings>0) {
printf(" all-unassigned sequences from initial state %ld use %ld bytes\n",
(long)state, (long)savings);
}
}
}
}
//Main solver function
bool fillSudoku()
{
int row, col;
//Check whether grid is filled; if not then return first unassigned value
if(!findUnassigned(row, col))
{
return TRUE;
}
//Backtracking is used here.
int num;
for(num=1;num<SIZE+1;num++)
{
if(checkSafe(row,col,num))
{
cell[row][col]=num;
if(fillSudoku()) return TRUE;
cell[row][col]=0;
}
}
return FALSE;
}
