c程課件part4-ch71基本運算

1、簡單數(shù)據(jù)的描述及其操作方法built-in daype & operator2013.10劉奇志Part 42Chapter 73/+-*-/%/+ /-+ +-*/% /7.1C/double x, y, z;char operatr;prf(input an expres: x+(-)yn);scanf(%lf%c%lf, &x, &operatr, &y);switch(operatr)case +:case -: default:z = x + y;z = x - y;break;break;prf(error!n);prf( = %f n, z); 10.8+0.13= 10. 93

2、0000/實現(xiàn)連續(xù)的加/減法prf(input expres: x+(-)y +(-)z =n);scanf(%lf, &x);while(operate = getchar( ) != =)scanf(%lf, &y); switch(operate)case +:case -: default:x += y;x -= y;break;break;prf(error!n); goto END;pr END:f(%f n, x);/實現(xiàn)連續(xù)的加/減法810.8+0.13-10=0.930000C* Cx*x(x, y)xymath.hxy i = 2a; /!my(x,n)z = 1;whil

3、e(n = 1)z *= x; n-;return z; C/ C03/21 1/20-10/3-30 7.2 10-61 1 1 1 .4#include #include double myPi();357main( )prf(: %f n, myPi();return 0; double myPi()sign = 1;double item = 1.0, sum = 1.0;for(n = 1; fabs(item) 1e-6; n+)sign = -sign;/運用了取負操作item = sign * 1 / (2 * n + 1);sum += item;/應改成item = sig

4、n * 1.0 / (2 * n + 1);return 4 * sum;13Cscore = 0; scanf(%d, &score); switch(score / 10)case 10:/_score 100 apr/_score 90-99 /_score 80-89 /_score 70-79 /_score 60-69 /_score 8DC f(A case 9: prcase 8: prcase 7: prcase 6: pr default: prf(A n); break;f(B n); break;f(C n); break;f(D n); break;f(Fail n)

5、; C%mn(m/n)*n+m%nm157.3153 1333 53for(n = 100; n = 0 & n 0) r = m % n;else if(m 0 & n 0)r = (-m) % (-n);else if(m 0) r = -(-m) % n);elser = -(m % (-n);prprf(The quotient is %d n, q);f(The remainder is %d n, r);18分支語句將負數(shù)的求余數(shù)運算統(tǒng) 一成：先求兩個正數(shù)的余數(shù)，再 根據(jù)商的正負考慮是否添加負號，以避免程序的歧義。/+/-1/1 m = 3;m+;/mV , 4m-;/mV ,2

6、3n = m+;/mV , 4 nV 3i = 3;+i;/W i += 1 +i = i +1 iV , 4-i;/W i -= 1 +i = i -1 iV ,2 3j = +i;/W=!= != 7.5w 1515 ! w 3030 ! w 4545 ! w 60w 60591214100011510002Cwd #include Charge(weight,distance);main( )w, d;f(Please input the weight and the distance : n);prscanf(%d%d, &w, &d); while(w = 0 | d = 0)prf

7、(The input is wrong! Please input again: n);scanf(%d%d, &w, &d);prf(%d n, Charge(w, d) );return 0;2324Charge(weight,distance)money = 0;if(weight 15) money = 5; else if(weight 30) money = 9; else if(weight 45) money = 12;else if(weight 60) money = 14 + distance/1000;else money = 15 + (distance/1000)

8、* 2; return money;25Charge(weight,distance)money = 0; switch(weight /15)case 0: money = 5; break;case 1: money = 9; break;case 2: money = 12; break; default:if(weight 1e-6; n+)sign = -sign;/item = sign * 1 / (2 * n + 1);sum += item;/item = sign * 1.0 / (2 * n + 1);return 4 * sum; fabs(item) != 1e-6I

9、.Q=U=if(n = 0)n+;else/if(n = 0)n0n = 1 / n;if(0 = n)n+;else/if(0 = n)n = 1 / n; C!&| !(a b)aba3b4(age 50)age10weight50age8weight52(ch 9)ch7ch09 (short-circuit evaluation)&| & x | x “”guard(number != 0) & (1/number 0.5)number0 De Man!(a&b)!(a|b)!(a&b)|c)(!a)|(!b)(!a)&(!b)(!a|!b)&!c 7.6 cock, hen, chi

10、cken;prf(*百雞問題*n);for (cock = 0; cock = 100; cock+) for (hen = 0; hen = 100; hen+)101for (chicken = 0; chicken = 100; chicken += 3)10133if ( cock + hen + chicken = 100 &cock*5 + hen*3 + chicken/3 = 100 )prf(%3d %3d %3d n, cock, hen, chicken);33循環(huán)次數(shù)的計算：外循環(huán)執(zhí)行101次，每次中間循環(huán)需要執(zhí)行101次， 中間循環(huán)執(zhí)行一次內(nèi)層循環(huán)需要執(zhí)行33次，因此

11、內(nèi)層循環(huán)體if語句需要判斷約33萬次。cock, hen, chicken;prf(*百雞問題*n);for (cock = 0; cock = 20; cock+) for (hen = 0; hen = 33; hen+)21for (chicken = 0; chicken = 100-cock-hen; chicken += 3)33if ( cock + hen + chicken = 100 &cock*5 + hen*3 + chicken/3 = 100 )33prf(%3d %3d %3d n, cock, hen, chicken);34循環(huán)次數(shù)的計算：外循環(huán)執(zhí)行21次，每次中間循環(huán)需要執(zhí)行33次， 中間循環(huán)執(zhí)行一次內(nèi)層循環(huán)最多執(zhí)行33次，因此內(nèi)層循環(huán)體if語句判斷 2萬次。優(yōu)化方案一cock, hen, chicken;prf(*百雞問題*n);for (cock = 0; cock = 20; coc