Đề bài tập

#0001

#0001. GIY CHNG CH

Steve tham gia rt nhiu k thi, lp ngoi kha khc nhau v c cc loi chng ch. Cc chng ch ny c kp lu tr cc tp khc nhau khng theo mt quy tc no c. Cng may l bn ngoi tp cn ghi s lng chng ch kp trong .

Hm nay Steve cn i ra vn phng cng chng sao li chng ch kt qu thi Tin hc Quc gia lm h s xin c tuyn thng vo khoa Cng ngh thng tin. Steve ch c mt chng ch ny. Bn y mun tm tp cha cha chng ch ang cn, mang ra ni cng chng v trong thi gian xp hng ch i s tm v ly n ra sao. Vic m mt tp kp chng ch mt 1 giy, xem xt mt chng ch c phi l ci mnh ang tm hay khng cng mt 1 giy. D nhin Steve khng tm cc tp c ghi s lng l 0. Vic chuyn t tp ny sang tp khc l khng ng k.

Yu cu: Cho n s tp lu chng ch v cc s ai s chng ch lu trong tp i ( 0 ai 106, 1 n 106, i = 1 n). Hy xc nh, trong trng hp xu nht, Steve cn t nht bao nhiu thi gian tm ra tp cn thit.

D liu: Vo t file vn bn CERTIF.INP:

+ Dng u tin cha s nguyn n,

+ Dng th 2 cha n s nguyn a1, a2, . . ., an.

Kt qu: a ra file vn bn CERTIF.OUT mt s nguyn thi gian cn tm.

V d:

CERTIF.INPCERTIF.OUT

4

1 0 2 14

3

1 2 35

Tag: tm kim

Hng dn:

Steven s mt t thi gian nht tm chng ch khi chng ch nm trong tp dy nht do vy ta s tm tp chng ch c s lng ln nht sau m thi gian cn thit Steven tm trong cc tp cn li. d lp trnh ta thc hin theo cc bc:

B1: tm v tr vt l v tr c avt ln nht

B2: a1 a1B3: m: tongtong+ai+1 nu ai>0 (i=2,n)

#0002: I S NH PHN SANG H C S 16

Cho S l mt xu ch gm 2 k t '0' hoc '1' m t mt s nguyn khng m h c s 2. Hy chuyn s sang h c s 16V d: 101011002=AC16#0003: XP HANG MUA VE

C N ngi sp hng mua v d bui ho nhc. Ta nh s h t 1 n N theo th t ng trong hng. Mi ngi cn mua mt v, song ngi bn v c php bn cho mi ngi ti a hai v. V th, mt s ngi c th ri hng v nh ngi ng trc mnh mua h v. Bit ti l thi gian cn thit ngi i mua xong v cho mnh. Nu ngi i+1 ri khi hng v nh ngi i mua h v th thi gian ngi th i mua c v cho c hai ngi l ri.

Yu cu: Xc nh xem nhng ngi no cn ri khi hng v nh ngi ng trc mua h v tng thi gian phc v bn v l nh nht.

D liu vao: t tp NKTICK.INP

+ Dng u tin cha s N (1 N 60000).

+ Dng th 2 ghi N s nguyn dng t1, t2, ..., tN. (1 ti 30000)

+ Dng th ba ghi N-1 s nguyn dng r1, r2, ..., rN-1. (1 ri 30000)

D liu ra: ghi vao tp NKTICK.OUT

In ra tng thi gian phc v nh nht

Vi du:

NKTICK.INPNKTICK.OUT

5

2 5 7 8 4

4 9 10 1018

4

5 7 8 4

50 50 5024

Tag: quy hoch ng

Hng dn:

+ Goi T[i] la thi gian ngn nht i ngi u tin mua ve.

+ Nu chi co 1 ngi: T[1]A[1];

+ Cng thc: T[i]min(A[i]+T[i-1],B[i-1]+T[i-2]) vi i=2 n N

+ Kt qua: T[N]

#0004: CHUT V KHOAI LANG

Trong mt mnh vn hnh ch nht c kch thc MxN, ngi ta chia mnh vn thnh M hng v N ct, cc hng v ct to thnh cc n v hnh vung c cnh bng 1, ngi ta trng khoai lang trong nhng n v hnh vung. Trong mnh vn ny c mt ch chut trong hang, ch chut ny cn xc nh min (Hai min khc nhau khng c mt cnh vung no chung) ngi ta trng khoai lang c din tch ln nht trong mnh vn o mt ng hm n phn din tch ln nht . Hy vit chng trnh gip ch chut thc hin cng vic o hm

D liu: t tp tin vn bn CHUOT.INP

+ Dng u tin ghi 2 s nguyn dng M v N l kch thc ca mnh vn (1M,N100).

+ Trong M dng tip theo, mi dng c N k t 0 hoc 1, vi ngha 0 l khng trng khoai lang, 1 l c trng khoai lang

Kt qu: Ghi vo tp tin vn bn CHUOT.OUT mt s nguyn l tng s dy khoai lang ca min c din tch ln nht (gi s mi ch c ti a mt dy khoai lang)

V d:

CHUOT.INPCHUOT.OUT

6 6

000111

000011

000011

000011

000011

11100011

Tag: Loang, BFS

Hng dn: Thut ton loang trn mng hai chiu

#0005: GHP S

Cho hai s t nhin A c N ch s v B c M ch s (2