《进位也可以很有趣》PPT课件.ppt

Binary-1,二進位也可以很有趣,32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,Binary-2,二進位也可以很有趣,16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63,Binary-3,二進位也可以很有趣,8, 9, 10, 11, 12, 13, 14, 15, 24, 25, 26, 27, 28, 29, 30, 31, 40, 41, 42, 43, 44, 45, 46, 47, 56, 57, 58, 59, 60, 61, 62, 63,Binary-4,二進位也可以很有趣,4, 5, 6, 7, 12, 13, 14, 15, 20, 21, 22, 23, 28, 29, 30, 31, 36, 37, 38, 39, 44, 45, 46, 47, 52, 53, 54, 55, 60, 61, 62, 63,Binary-5,二進位也可以很有趣,2, 3, 6, 7, 10, 11, 14, 15, 18, 19, 22, 23, 26, 27, 30, 31, 34, 35, 38, 39, 42, 43, 46, 47, 50, 51, 54, 55, 58, 59, 62, 63,Binary-6,二進位也可以很有趣,1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63,Binary-7,二進位也可以很有趣(原理),1, 3, 5, 7, 0 0 0 0 0 1 = 1 9, 11, 13, 15, 0 0 0 0 1 0 = 2 17, 19, 21, 23, 0 0 0 0 1 1 = 3 25, 27, 29, 31, 0 0 0 1 0 0 = 4 33, 35, 37, 39, 0 0 0 1 0 1 = 5 41, 43, 45, 47, 0 0 0 1 1 0 = 6 49, 51, 53, 55, 0 0 0 1 1 1 = 7 57, 59, 61, 63 0 0 1 0 0 0 = 8,Binary-8,二進位也可以很有趣(原理),2, 3, 6, 7, 0 0 0 0 0 1 = 1 10, 11, 14, 15, 0 0 0 0 1 0 = 2 18, 19, 22, 23, 0 0 0 0 1 1 = 3 26, 27, 30, 31, 0 0 0 1 0 0 = 4 34, 35, 38, 39, 0 0 0 1 0 1 = 5 42, 43, 46, 47, 0 0 0 1 1 0 = 6 50, 51, 54, 55, 0 0 0 1 1 1 = 7 58, 59, 62, 63 0 0 1 0 0 0 = 8,Binary-9,二進位也可以很有趣(原理),4, 5, 6, 7, 0 0 0 0 0 1 = 1 12, 13, 14, 15, 0 0 0 0 1 0 = 2 20, 21, 22, 23, 0 0 0 0 1 1 = 3 28, 29, 30, 31, 0 0 0 1 0 0 = 4 36, 37, 38, 39, 0 0 0 1 0 1 = 5 44, 45, 46, 47, 0 0 0 1 1 0 = 6 52, 53, 54, 55, 0 0 0 1 1 1 = 7 60, 61, 62, 63 0 0 1 0 0 0 = 8,Binary-10,二進位也可以很有趣(原理),8, 9, 10, 11, 0 0 0 1 1 1 = 7 12, 13, 14, 15, 0 0 1 0 0 0 = 8 24, 25, 26, 27, 0 0 1 0 0 1 = 9 28, 29, 30, 31, 0 0 1 0 1 0 = 10 40, 41, 42, 43, 0 0 1 0 1 1 = 11 44, 45, 46, 47, 0 0 1 1 0 0 = 12 56, 57, 58, 59, 0 0 1 1 0 1 = 13 60, 61, 62, 63 0 0 1 1 1 0 = 14,Binary-11,二進位也可以很有趣(原理),16, 17, 18, 19, 0 1 0 0 0 0 = 16 20, 21, 22, 23, 0 1 0 0 0 1 = 17 24, 25, 26, 27, 0 1 0 0 1 0 = 18 28, 29, 30, 31, 0 1 0 0 1 1 = 19 48, 49, 50, 51, 0 1 0 1 0 0 = 20 52, 53, 54, 55, 0 1 0 1 0 1 = 21 56, 57, 58, 59, 0 1 0 1 1 0 = 22 60, 61, 62, 63 0 1 0 1 1 1 = 23,Binary-12,二進位也可以很有趣(原理),32, 33, 34, 35, 1 0 0 0 0 0 = 32 36, 37, 38, 39, 1 0 0 0 0 1 = 33 40, 41, 42, 43, 1 0 0 0 1 0 = 34 44, 45, 46, 47, 1 0 0 0 1 1 = 35 48, 49, 50, 51, 1 0 0 1 0 0 = 36 52, 53, 54, 55, 1 0 0 1 0 1 = 37 56, 57, 58, 59, 1 0 0 1 1 0 = 38 60, 61, 62, 63 1 0 0 1 1 1 = 39,卡片玩法與原理,請玩者心裡想一個0到63的整數不要告訴你(廢話), 然後你依第六張、 第五張、第四張 . 第一張拿給他, 請他告訴你上面有沒有他想的數, 為了表示你是過目不忘, 交給他之前假裝看一看, 交給他後不要立刻 拿回來, 只請他分別放不同手中作為證據。 答案: 如果六張都沒有就是 0。 在每張給他之前看清楚第一個數, 只要他說有就加到答案中, 等到 最後一張給他, 等他說出有沒有後, 答案也出來了。 原理: 其實每張紙都是代表一個二進位數 (binary number)。 有就是 1, 沒有就是 0。 與上一遊戲一樣, 他已經把答案告訴你了 ! 因每張紙上第一位數就是該位的比重(weight, 加權)。,Binary-14,二進位也可以很有趣,/* 寫程式印出前述之六張卡片 */ for( int i=0; i = 5; i+) printf(“二進位也可以很有趣nn “); /* 印出第 i 張卡片 */ printf(“nnn“); ,Binary-15,二進位也可以很有趣,for( int i=0; i = 5; i+) printf(“二進位也可以很有趣nn “); for(k=0; k = 63; k+) if( k ,Binary-16,int yy = 1, 2, 4, 8, 16, 32;,for( int i=0; i = 5; i+) printf(“二進位也可以很有趣nn “); for(k=0; k = 63; k+) if( k 用一個陣列記住 2的 i 次方,Binary-17,if(必要時) printf(“n“);,int np = 0; /* numbers printed */ for(k=0; k = 63; k+) if( k ,Binary-18,if(必要時) printf(“n“);,int np = 0; for(k=0; k = 63; k+) if( k / 每印完八個數就換列 (new line) ,Binary-19,二進位也可以很有趣完整程式,/* 寫程式印出前述之六張卡片 */ #include int yy = 1, 2, 4, 8, 16, 32; int k, np; main( ) for( int i=0; i = 5; i+) printf(“二進位也可以很有趣nn “); np=0; /* 印出第 i 張卡片 */ printf(“nnn“); ,Binary-20,問題與思考,* 為什麼要依第六張(32開頭那張)、 第五張、 第四張 . 第一張拿給玩者? * 如果不用一個table (array) 來記住2的i 次方, 那要怎麼做? 用乘的 有何缺點? * 每張卡片最後一列也印了逗點, 如何改進? (hint: 加一列 if ),Binary-21,問題與思考 (ASCII code ),#include main( ) printf(“ %c 的 ASCII code是%dn“, 0, 0); printf(“ %c 的 ASCII code是%dn“, A, A); printf(“ %c 的 ASCII code是%dn“, a, a); 如果系統使用EBCDIC碼呢?,Binary-22,問題與思考 (ASCII code ),#include main( ) int i, k=0; for(i=65; i=122; +i) printf(“ %c 的 ASCII code“, i); printf(“ 是%d“, i); +k; printf(k%3=0? “n“ : “t“); printf(“n“ ); ,Binary-23,問題與思考 (中文碼?),#include unsigned char x9 = 0 ; main( ) int m = 0xa4, n=0x6a; x0 = m; x1=n; x2 = 0xae, x3=97; x4 = 0xa6, x5=0x6e; printf(“=%s=n“, x); ,Binary-24,Binary-25,實數與準確度(precision),#include float x, xdelta; int i; /*precision.c */ main( ) double y; x = 1234567.2, xdelta = 0.0001; printf(“Before loop, x=%fn“, x); for(i=1; i= 8000; i+) y = x + xdelta; /*/ if(i = 1) printf(“first y = %fn“, y); x = y; printf(“After loop, x=%fn“, x); ,Binary-26,float 實數準確度七位多,ccbsd2:precision/ gcc precision.c ccbsd2:precision/ ./a.out Before loop, x=1234567.250000 first y = 1234567.250100 After loop, x=1234567.250000 ccbsd2:precision/ float 實數佔用 32 bits,Binary-27,double 實數準確度,#include double x, xdelta; int i; /*precdbl.c */ main( ) double y; x = 1234567.2, xdelta = 0.0001; printf(“Before loop, x=%fn“, x); for(i=1; i= 8000; i+) y = x + xdelta; /*/ if(i = 1) printf(“first y = %fn“