函数专题培训市公开课金奖市赛课一等奖课件.pptx

第三章函数本章主要内容函数申明函数申明函数调用例3-1编写一个求xn次方函数运营结果：5tothepower2is25例3-2数制转换#include<iostream>usingnamespacestd;doublepower(doublex,intn);voidmain(void){inti;intvalue=0;charch;cout<<"Enteran8bitbinarynumber";for(i=7;i>=0;i--){cin>>ch;if(ch=='1')value+=int(power(2,i));}cout<<"Decimalvalueis"<<value<<endl;}doublepower(doublex,intn){doubleval=1.0;while(n--)val*=x;return(val);}例3-3编写程序求π值#include<iostream>usingnamespacestd;voidmain(){doublea,b;doublearctan(doublex);//函数原型申明a=16.0*arctan(1/5.0);b=4.0*arctan(1/239.0);//注意：由于整数相除结果取整，//假如参数写1/5，1/239，结果就都是0cout<<"PI="<<a-b<<endl;}doublearctan(doublex){inti;doubler,e,f,sqr;sqr=x*x;r=0;e=x;i=1;while(e/i>1e-15){f=e/i;r=(i%4==1)?r+f:r-f;e=e*sqr;i+=2;}returnr;}例3-4#include<iostream>usingnamespacestd;voidmain(){boolsymm(longn);longm;for(m=11;m<1000;m++)if(symm(m)&&symm(m*m)&&symm(m*m*m))cout<<"m="<<m<<"m*m="<<m*m<<"m*m*m="<<m*m*m<<endl;}boolsymm(longn){longi,m;i=n;m=0;while(i){m=m*10+i%10;i=i/10;}return(m==n);}运营结果：m=11m*m=121m*m*m=1331m=101m*m=10201m*m*m=1030301m=111m*m=12321m*m*m=1367631例3-5#include<iostream>#include<cmath>usingnamespacestd;voidmain(){doublek,r,s;doubletsin(doublex);cout<<"r=";cin>>r;cout<<"s=";cin>>s;if(r*r<=s*s)k=sqrt(tsin(r)*tsin(r)+tsin(s)*tsin(s));elsek=tsin(r*s)/2;cout<<k<<endl;}doubletsin(doublex){doublep=0.000001,g=0,t=x;intn=1;do{g=g+t;n++;t=-t*x*x/(2*n-1)/(2*n-2);}while(fabs(t)>=p);returng;}例3-6投骰子随机游戏#include<iostream>#include<cstdlib>usingnamespacestd;introlldice(void);voidmain(){intgamestatus,sum,mypoint;unsignedseed;cout<<"Pleaseenteranunsignedinteger:";cin>>seed;//输入随机数种子srand(seed);//将种子传递给rand()sum=rolldice();//第一轮投骰子、计算和数switch(sum){case7://假如和数为7或11则为胜,状态为1case11:gamestatus=1;break;case2://和数为2、3或12则为负,状态为2case3:case12:gamestatus=2;break;default://其它情况,游戏尚无结果,状态为0,记下点数,为下一轮做准备gamestatus=0;mypoint=sum;cout<<"pointis"<<mypoint<<endl;break;}while(gamestatus==0)//只要状态仍为0,就继续进行下一轮{sum=rolldice();if(sum==mypoint)//某轮和数等于点数则取胜,状态置为1gamestatus=1;elseif(sum==7)//出现和数为7则为负,状态置为2gamestatus=2;}//当状态不为0时上面循环结束,下列