long Ext2InitPartition(CICell ih)
{
long cnt, gdPerBlock;
if (ih == gCurrentIH) return 0;
printf("Ext2InitPartition: %x\n", ih);
gCurrentIH = 0;
// Read for the Super Block.
Seek(ih, SBOFF);
Read(ih, (long)gFSBuf, SBSIZE);
gFS = (struct m_ext2fs *)gFSBuf;
e2fs_sb_bswap(&gFS->e2fs, &gFS->e2fs);
if (gFS->e2fs.e2fs_magic != E2FS_MAGIC) return -1;
// Calculate the block size and set up the block cache.
gBlockSize = 1024 << gFS->e2fs.e2fs_log_bsize;
if (gBlockSizeOld <= gBlockSize) {
gTempBlock = AllocateBootXMemory(gBlockSize);
}
CacheInit(ih, gBlockSize);
gBlockSizeOld = gBlockSize;
gCurrentIH = ih;
gdPerBlock = gBlockSize / sizeof(struct ext2_gd);
// Fill in the in memory super block fields.
gFS->e2fs_bsize = 1024 << gFS->e2fs.e2fs_log_bsize;
gFS->e2fs_bshift = LOG_MINBSIZE + gFS->e2fs.e2fs_log_bsize;
gFS->e2fs_qbmask = gFS->e2fs_bsize - 1;
gFS->e2fs_bmask = ~gFS->e2fs_qbmask;
gFS->e2fs_fsbtodb = gFS->e2fs.e2fs_log_bsize + 1;
gFS->e2fs_ncg = HowMany(gFS->e2fs.e2fs_bcount - gFS->e2fs.e2fs_first_dblock,
gFS->e2fs.e2fs_bpg);
gFS->e2fs_ngdb = HowMany(gFS->e2fs_ncg, gdPerBlock);
gFS->e2fs_ipb = gFS->e2fs_bsize / EXT2_DINODE_SIZE;
gFS->e2fs_itpg = gFS->e2fs.e2fs_ipg / gFS->e2fs_ipb;
gFS->e2fs_gd = AllocateBootXMemory(gFS->e2fs_ngdb * gFS->e2fs_bsize);
// Read the summary information from disk.
for (cnt = 0; cnt < gFS->e2fs_ngdb; cnt++) {
ReadBlock(((gBlockSize > 1024) ? 0 : 1) + cnt + 1, 0, gBlockSize,
(char *)&gFS->e2fs_gd[gdPerBlock * cnt], 0);
e2fs_cg_bswap(&gFS->e2fs_gd[gdPerBlock * cnt],
&gFS->e2fs_gd[gdPerBlock * cnt], gBlockSize);
}
// Read the Root Inode
ReadInode(EXT2_ROOTINO, &gRootInode, 0, 0);
return 0;
}
int main() {
scanf("%d", &n);
for (int i = 1; i <= n; i += 1) {
scanf("%d", &marbles[i]);
}
Init();
int answer = n;
int num_white = HowMany(1, n, white);
int num_black = n - num_white;
for (int i = 1; i + num_white - 1 <= n; i += 1) {
int num_swaps = HowMany(i, num_white, black);
answer = min(answer, num_swaps);
}
for (int i = 1; i + num_black - 1 <= n; i += 1) {
int num_swaps = HowMany(i, num_black, white);
answer = min(answer, num_swaps);
}
printf("%d\n", answer);
return 0;
}
WORD DoIfStatement(PHEAD WORD *ifcode, WORD *term)
{
GETBIDENTITY
WORD *ifstop, *ifp;
UWORD *coef1 = 0, *coef2, *coef3, *cc;
WORD ncoef1, ncoef2, ncoef3, i = 0, first, *r, acoef, ismul1, ismul2, j;
UWORD *Spac1, *Spac2;
ifstop = ifcode + ifcode[1];
ifp = ifcode + 3;
if ( ifp >= ifstop ) return(1);
if ( ( ifp + ifp[1] ) >= ifstop ) {
switch ( *ifp ) {
case LONGNUMBER:
if ( ifp[2] ) return(1);
else return(0);
case MATCH:
case TYPEIF:
if ( HowMany(BHEAD ifp,term) ) return(1);
else return(0);
case TYPEFINDLOOP:
if ( Lus(term,ifp[3],ifp[4],ifp[5],ifp[6],ifp[2]) ) return(1);
else return(0);
case TYPECOUNT:
if ( CountDo(term,ifp) ) return(1);
else return(0);
case COEFFI:
case MULTIPLEOF:
return(1);
case IFDOLLAR:
{
DOLLARS d = Dollars + ifp[2];
#ifdef WITHPTHREADS
int nummodopt, dtype = -1;
if ( AS.MultiThreaded ) {
for ( nummodopt = 0; nummodopt < NumModOptdollars; nummodopt++ ) {
if ( ifp[2] == ModOptdollars[nummodopt].number ) break;
}
if ( nummodopt < NumModOptdollars ) {
dtype = ModOptdollars[nummodopt].type;
if ( dtype == MODLOCAL ) {
d = ModOptdollars[nummodopt].dstruct+AT.identity;
}
}
}
dtype = d->type;
#else
int dtype = d->type; /* We use dtype to make the operation atomic */
#endif
if ( dtype == DOLZERO ) return(0);
if ( dtype == DOLUNDEFINED ) {
if ( AC.UnsureDollarMode == 0 ) {
MesPrint("$%s is undefined",AC.dollarnames->namebuffer+d->name);
Terminate(-1);
}
}
}
return(1);
case IFEXPRESSION:
r = ifp+2; j = ifp[1] - 2;
while ( --j >= 0 ) {
if ( *r == AR.CurExpr ) return(1);
r++;
}
return(0);
case IFISFACTORIZED:
r = ifp+2; j = ifp[1] - 2;
if ( j == 0 ) {
if ( ( Expressions[AR.CurExpr].vflags & ISFACTORIZED ) != 0 )
return(1);
else
return(0);
}
while ( --j >= 0 ) {
if ( ( Expressions[*r].vflags & ISFACTORIZED ) == 0 ) return(0);
r++;
}
return(1);
case IFOCCURS:
{
WORD *OccStop = ifp + ifp[1];
ifp += 2;
while ( ifp < OccStop ) {
if ( FindVar(ifp,term) == 1 ) return(1);
if ( *ifp == DOTPRODUCT ) ifp += 3;
else ifp += 2;
}
}
return(0);
default:
/*
Now we have a subexpression. Test first for one with a single item.
*/
if ( ifp[3] == ( ifp[1] + 3 ) ) return(DoIfStatement(BHEAD ifp,term));
ifstop = ifp + ifp[1];
ifp += 3;
break;
}
}
/*
Here is the composite condition.
*/
coef3 = NumberMalloc("DoIfStatement");
Spac1 = NumberMalloc("DoIfStatement");
Spac2 = (UWORD *)(TermMalloc("DoIfStatement"));
ncoef1 = 0; first = 1; ismul1 = 0;
do {
if ( !first ) {
ifp += 2;
if ( ifp[-2] == ORCOND && ncoef1 ) {
coef1 = Spac1;
ncoef1 = 1; coef1[0] = coef1[1] = 1;
goto SkipCond;
}
if ( ifp[-2] == ANDCOND && !ncoef1 ) goto SkipCond;
}
coef2 = Spac2;
ncoef2 = 1;
ismul2 = 0;
switch ( *ifp ) {
case LONGNUMBER:
ncoef2 = ifp[2];
j = 2*(ABS(ncoef2));
cc = (UWORD *)(ifp + 3);
for ( i = 0; i < j; i++ ) coef2[i] = cc[i];
break;
case MATCH:
case TYPEIF:
coef2[0] = HowMany(BHEAD ifp,term);
coef2[1] = 1;
if ( coef2[0] == 0 ) ncoef2 = 0;
break;
case TYPECOUNT:
acoef = CountDo(term,ifp);
coef2[0] = ABS(acoef);
coef2[1] = 1;
if ( acoef == 0 ) ncoef2 = 0;
else if ( acoef < 0 ) ncoef2 = -1;
break;
case TYPEFINDLOOP:
acoef = Lus(term,ifp[3],ifp[4],ifp[5],ifp[6],ifp[2]);
coef2[0] = ABS(acoef);
coef2[1] = 1;
if ( acoef == 0 ) ncoef2 = 0;
else if ( acoef < 0 ) ncoef2 = -1;
break;
case COEFFI:
r = term + *term;
ncoef2 = r[-1];
i = ABS(ncoef2);
cc = (UWORD *)(r - i);
if ( ncoef2 < 0 ) ncoef2 = (ncoef2+1)>>1;
else ncoef2 = (ncoef2-1)>>1;
i--; for ( j = 0; j < i; j++ ) coef2[j] = cc[j];
break;
case SUBEXPR:
ncoef2 = coef2[0] = DoIfStatement(BHEAD ifp,term);
coef2[1] = 1;
break;
case MULTIPLEOF:
ncoef2 = 1;
coef2[0] = ifp[2];
coef2[1] = 1;
ismul2 = 1;
break;
case IFDOLLAREXTRA:
break;
case IFDOLLAR:
{
/*
We need to abstract a long rational in coef2
with length ncoef2. What if that cannot be done?
*/
DOLLARS d = Dollars + ifp[2];
#ifdef WITHPTHREADS
int nummodopt, dtype = -1;
if ( AS.MultiThreaded ) {
for ( nummodopt = 0; nummodopt < NumModOptdollars; nummodopt++ ) {
if ( ifp[2] == ModOptdollars[nummodopt].number ) break;
}
if ( nummodopt < NumModOptdollars ) {
dtype = ModOptdollars[nummodopt].type;
if ( dtype == MODLOCAL ) {
d = ModOptdollars[nummodopt].dstruct+AT.identity;
}
else {
LOCK(d->pthreadslockread);
}
}
}
#endif
/*
We have to pick up the IFDOLLAREXTRA pieces for [1], [$y] etc.
*/
if ( ifp+3 < ifstop && ifp[3] == IFDOLLAREXTRA ) {
if ( d->nfactors == 0 ) {
MLOCK(ErrorMessageLock);
MesPrint("Attempt to use a factor of an unfactored $-variable");
MUNLOCK(ErrorMessageLock);
Terminate(-1);
} {
WORD num = GetIfDollarNum(ifp+3,ifstop);
WORD *w;
while ( ifp+3 < ifstop && ifp[3] == IFDOLLAREXTRA ) ifp += 3;
if ( num > d->nfactors ) {
MLOCK(ErrorMessageLock);
MesPrint("Dollar factor number %s out of range",num);
MUNLOCK(ErrorMessageLock);
Terminate(-1);
}
if ( num == 0 ) {
ncoef2 = 1; coef2[0] = d->nfactors; coef2[1] = 1;
break;
}
w = d->factors[num-1].where;
if ( w == 0 ) {
if ( d->factors[num-1].value < 0 ) {
ncoef2 = -1; coef2[0] = -d->factors[num-1].value; coef2[1] = 1;
}
else {
ncoef2 = 1; coef2[0] = d->factors[num-1].value; coef2[1] = 1;
}
break;
}
if ( w[*w] == 0 ) {
r = w + *w - 1;
i = ABS(*r);
if ( i == ( *w-1 ) ) {
ncoef2 = (i-1)/2;
if ( *r < 0 ) ncoef2 = -ncoef2;
i--; cc = coef2; r = w + 1;
while ( --i >= 0 ) *cc++ = (UWORD)(*r++);
break;
}
}
goto generic;
}
}
else {
switch ( d->type ) {
case DOLUNDEFINED:
if ( AC.UnsureDollarMode == 0 ) {
#ifdef WITHPTHREADS
if ( dtype > 0 && dtype != MODLOCAL ) { UNLOCK(d->pthreadslockread); }
#endif
MLOCK(ErrorMessageLock);
MesPrint("$%s is undefined",AC.dollarnames->namebuffer+d->name);
MUNLOCK(ErrorMessageLock);
Terminate(-1);
}
ncoef2 = 0; coef2[0] = 0; coef2[1] = 1;
break;
case DOLZERO:
ncoef2 = coef2[0] = 0; coef2[1] = 1;
break;
case DOLSUBTERM:
if ( d->where[0] != INDEX || d->where[1] != 3
|| d->where[2] < 0 || d->where[2] >= AM.OffsetIndex ) {
if ( AC.UnsureDollarMode == 0 ) {
#ifdef WITHPTHREADS
if ( dtype > 0 && dtype != MODLOCAL ) { UNLOCK(d->pthreadslockread); }
#endif
MLOCK(ErrorMessageLock);
MesPrint("$%s is of wrong type",AC.dollarnames->namebuffer+d->name);
MUNLOCK(ErrorMessageLock);
Terminate(-1);
}
ncoef2 = 0; coef2[0] = 0; coef2[1] = 1;
break;
}
d->index = d->where[2];
case DOLINDEX:
if ( d->index == 0 ) {
ncoef2 = coef2[0] = 0; coef2[1] = 1;
}
else if ( d->index > 0 && d->index < AM.OffsetIndex ) {
ncoef2 = 1; coef2[0] = d->index; coef2[1] = 1;
}
else if ( AC.UnsureDollarMode == 0 ) {
#ifdef WITHPTHREADS
if ( dtype > 0 && dtype != MODLOCAL ) { UNLOCK(d->pthreadslockread); }
#endif
MLOCK(ErrorMessageLock);
MesPrint("$%s is of wrong type",AC.dollarnames->namebuffer+d->name);
MUNLOCK(ErrorMessageLock);
Terminate(-1);
}
ncoef2 = coef2[0] = 0; coef2[1] = 1;
break;
case DOLWILDARGS:
if ( d->where[0] <= -FUNCTION ||
( d->where[0] < 0 && d->where[2] != 0 )
|| ( d->where[0] > 0 && d->where[d->where[0]] != 0 )
) {
if ( AC.UnsureDollarMode == 0 ) {
#ifdef WITHPTHREADS
if ( dtype > 0 && dtype != MODLOCAL ) { UNLOCK(d->pthreadslockread); }
#endif
MLOCK(ErrorMessageLock);
MesPrint("$%s is of wrong type",AC.dollarnames->namebuffer+d->name);
MUNLOCK(ErrorMessageLock);
Terminate(-1);
}
ncoef2 = coef2[0] = 0; coef2[1] = 1;
break;
}
case DOLARGUMENT:
if ( d->where[0] == -SNUMBER ) {
if ( d->where[1] == 0 ) {
ncoef2 = coef2[0] = 0;
}
else if ( d->where[1] < 0 ) {
ncoef2 = -1;
coef2[0] = -d->where[1];
}
else {
ncoef2 = 1;
coef2[0] = d->where[1];
}
coef2[1] = 1;
}
else if ( d->where[0] == -INDEX
&& d->where[1] >= 0 && d->where[1] < AM.OffsetIndex ) {
if ( d->where[1] == 0 ) {
ncoef2 = coef2[0] = 0; coef2[1] = 1;
}
else {
ncoef2 = 1; coef2[0] = d->where[1];
coef2[1] = 1;
}
}
else if ( d->where[0] > 0
&& d->where[ARGHEAD] == (d->where[0]-ARGHEAD)
&& ABS(d->where[d->where[0]-1]) ==
(d->where[0] - ARGHEAD-1) ) {
i = d->where[d->where[0]-1];
ncoef2 = (ABS(i)-1)/2;
if ( i < 0 ) { ncoef2 = -ncoef2; i = -i; }
i--; cc = coef2; r = d->where + ARGHEAD+1;
while ( --i >= 0 ) *cc++ = (UWORD)(*r++);
}
else {
if ( AC.UnsureDollarMode == 0 ) {
#ifdef WITHPTHREADS
if ( dtype > 0 && dtype != MODLOCAL ) { UNLOCK(d->pthreadslockread); }
#endif
MLOCK(ErrorMessageLock);
MesPrint("$%s is of wrong type",AC.dollarnames->namebuffer+d->name);
MUNLOCK(ErrorMessageLock);
Terminate(-1);
}
ncoef2 = 0; coef2[0] = 0; coef2[1] = 1;
}
break;
case DOLNUMBER:
case DOLTERMS:
if ( d->where[d->where[0]] == 0 ) {
r = d->where + d->where[0]-1;
i = ABS(*r);
if ( i == ( d->where[0]-1 ) ) {
ncoef2 = (i-1)/2;
if ( *r < 0 ) ncoef2 = -ncoef2;
i--; cc = coef2; r = d->where + 1;
while ( --i >= 0 ) *cc++ = (UWORD)(*r++);
break;
}
}
generic:;
if ( AC.UnsureDollarMode == 0 ) {
#ifdef WITHPTHREADS
if ( dtype > 0 && dtype != MODLOCAL ) { UNLOCK(d->pthreadslockread); }
#endif
MLOCK(ErrorMessageLock);
MesPrint("$%s is of wrong type",AC.dollarnames->namebuffer+d->name);
MUNLOCK(ErrorMessageLock);
Terminate(-1);
}
ncoef2 = 0; coef2[0] = 0; coef2[1] = 1;
break;
}
}
#ifdef WITHPTHREADS
if ( dtype > 0 && dtype != MODLOCAL ) { UNLOCK(d->pthreadslockread); }
#endif
}
break;
case IFEXPRESSION:
r = ifp+2; j = ifp[1] - 2; ncoef2 = 0;
while ( --j >= 0 ) {
if ( *r == AR.CurExpr ) { ncoef2 = 1; break; }
r++;
}
coef2[0] = ncoef2;
coef2[1] = 1;
break;
case IFISFACTORIZED:
r = ifp+2; j = ifp[1] - 2;
if ( j == 0 ) {
ncoef2 = 0;
if ( ( Expressions[AR.CurExpr].vflags & ISFACTORIZED ) != 0 ) {
ncoef2 = 1;
}
}
else {
ncoef2 = 1;
while ( --j >= 0 ) {
if ( ( Expressions[*r].vflags & ISFACTORIZED ) == 0 ) {
ncoef2 = 0;
break;
}
r++;
}
}
coef2[0] = ncoef2;
coef2[1] = 1;
break;
case IFOCCURS:
{
WORD *OccStop = ifp + ifp[1], *ifpp = ifp+2;
ncoef2 = 0;
while ( ifpp < OccStop ) {
if ( FindVar(ifpp,term) == 1 ) {
ncoef2 = 1; break;
}
if ( *ifpp == DOTPRODUCT ) ifp += 3;
else ifpp += 2;
}
coef2[0] = ncoef2;
coef2[1] = 1;
}
break;
default:
break;
}
if ( !first ) {
if ( ifp[-2] != ORCOND && ifp[-2] != ANDCOND ) {
if ( ( ifp[-2] == EQUAL || ifp[-2] == NOTEQUAL ) &&
( ismul2 || ismul1 ) ) {
if ( ismul1 && ismul2 ) {
if ( coef1[0] == coef2[0] ) i = 1;
else i = 0;
}
else {
if ( ismul1 ) {
if ( ncoef2 )
Divvy(BHEAD coef2,&ncoef2,coef1,ncoef1);
cc = coef2; ncoef3 = ncoef2;
}
else {
if ( ncoef1 )
Divvy(BHEAD coef1,&ncoef1,coef2,ncoef2);
cc = coef1; ncoef3 = ncoef1;
}
if ( ncoef3 < 0 ) ncoef3 = -ncoef3;
if ( ncoef3 == 0 ) {
if ( ifp[-2] == EQUAL ) i = 1;
else i = 0;
}
else if ( cc[ncoef3] != 1 ) {
if ( ifp[-2] == EQUAL ) i = 0;
else i = 1;
}
else {
for ( j = 1; j < ncoef3; j++ ) {
if ( cc[ncoef3+j] != 0 ) break;
}
if ( j < ncoef3 ) {
if ( ifp[-2] == EQUAL ) i = 0;
else i = 1;
}
else if ( ifp[-2] == EQUAL ) i = 1;
else i = 0;
}
}
goto donemul;
}
else if ( AddRat(BHEAD coef1,ncoef1,coef2,-ncoef2,coef3,&ncoef3) ) {
NumberFree(coef3,"DoIfStatement"); NumberFree(Spac1,"DoIfStatement"); TermFree(Spac2,"DoIfStatement");
MesCall("DoIfStatement"); return(-1);
}
switch ( ifp[-2] ) {
case GREATER:
if ( ncoef3 > 0 ) i = 1;
else i = 0;
break;
case GREATEREQUAL:
if ( ncoef3 >= 0 ) i = 1;
else i = 0;
break;
case LESS:
if ( ncoef3 < 0 ) i = 1;
else i = 0;
break;
case LESSEQUAL:
if ( ncoef3 <= 0 ) i = 1;
else i = 0;
break;
case EQUAL:
if ( ncoef3 == 0 ) i = 1;
else i = 0;
break;
case NOTEQUAL:
if ( ncoef3 != 0 ) i = 1;
else i = 0;
break;
}
donemul: if ( i ) { ncoef2 = 1; coef2 = Spac2; coef2[0] = coef2[1] = 1; }
else ncoef2 = 0;
ismul1 = ismul2 = 0;
}
}
else {
first = 0;
}
coef1 = Spac1;
i = 2*ABS(ncoef2);
for ( j = 0; j < i; j++ ) coef1[j] = coef2[j];
ncoef1 = ncoef2;
SkipCond:
ifp += ifp[1];
} while ( ifp < ifstop );
