北京信息科技大学大一C语言题库二.docx

程序填空】题目：下面程序运行后输出的结果是5,请填空ttinclude〃stdio.h〃main()inti=9;switch()(case5:i一一;case6:i一一;case7:i——;/slzslzvizslz1IIIslzslzslzslzslz//不不不不不不不不不不不「［ll不不不不不不不不不不不/i—；}printf(〃i=%d〃，i);【空1】【参考答案】i-4【空2】【参考答案】default:*【程序设计】功能：能计算从1开始到n的自然数的和，n由键盘输入，并在main()函数中输出/ttinclude〃stdio.h〃intfun(intn)/*********Begin**********//**********End**********/)main(){intm;fun(m));voidTestFunc();printf(z，Enterm:〃)；scanf(〃%d〃，&m);printf(，z\nTheresultis%d\n〃,TestFunc();}voidTestFunc(){FILE*IN,*0UT;intt;into;intc;IN二fopen(〃in.dat〃，〃r〃);if(IN=NULL){printf(Z/ReadFileError");}OUT二fopen(〃out.d&t〃，〃w〃);if(OUT=NULL)(printf(Z/WriteFileError");)for(c=l;c<=5;c++)(fscanf(IN,〃％d〃，&t);o二fun(t);fprintf(OUT,"%d\n〃,o);)fclose(IN);fclose(OUT);)【参考代码】intsum=0,i:for(i=l;i<=n;i++)sum=sum+i;return(sum);/*【程序改错】功能：利用公式法，求方程ax2+bx+c=0的解。

/ttincludettincludeintmain()doublea,b,c,disc,xl,x2,realpart,imagpart;sc&nf&a,&b,&c);disc=b*b-4*a*c;/**********ERR0R**********/if(abs(disc)<=le-6)printf("hastwoequalroots:%8.41f\n〃，-b/(2*a));/**********ERROR**********/if(disc>le-6)xl=(-b+sqrt(disc))/(2*a);x2=(-b-sqrt(disc))/(2*a);printf(''hasdistinctrealroots:%8.41fand%8.41f\n〃,xl,x2);else(realpart=-b/(2*a);imagpart=sqrt(-disc)/(2^a);printf(z/hascomplexroots:\n，z);printf(〃％8.41f+%8.41fi\n，z,realpart,imagpart);printf(〃%8・41f—%8.41fi\n〃,realpart,imagpart);return0;}【改错1】【参考答案】if(fabs(disc)<=le-6)【改错2】【参考答案】elseif(disc>le-6)【程序填空】题目：本程序用scanf函数,为变量x、y赋值，完善程序。

ttinclude"stdio.h"main()main()doublex,y;FILL***********/x=x+y;printf(,,\nx=%6.2f',,x);}【空1】【参考答案】&x,&y&y,&x/*【程序设计】题目：从键盘输入一个大写字母，要求改用小写字母输出/#include"stdio.h"charfun(charc)f——J；"^ili^/*//*T**T•个个个个个个*T*IJaaI人*T**T**T**t**T**T**T**T**iT**T*/End}voidmain()(charcl,c2;printf("Pleaseinputachar:");cl=getchar();printf("%c,%d\n",cl,cl);c2=fun(cl);printf("%c,%d\n",c2,c2);TestFunc();TestFunc()FILE*IN,*OUT;inti;chariINJOUT;IN=fopen("in.dat",,'r");if(IN==NULL){printf("PleaseVerifyTheCurrerntDir..ItMayBeChanged");}OUT=fopen(,,out.dat,,/,,w");if(OUT==NULL){printf("PleaseVerifyTheCurrentDir..ItMayBeChanged");}for(i=0;i<5;i++){fscanf(IN,”％c”,&ilN);iOUT=fun(ilN);fprintf(OU[”％c\n“,iOUT);}fclose(IN);fclose(OUT);}【参考代码】c=c+32;returnc;【程序改错】功能：求100以内（包括100）的偶数之和.includeHstdio.h"main()ERROR**********/inti,sum=l;/**********ERROR**********/for(i=2;i<=100;i+=l)sum+=i;/*ERROR**********/printf(HSum=%d\n";sum);【改错1】【参考答案】inti,sum=0;【改错2】【参考答案】for(i=2;i<=100;i+=2)for(i=2;i<=100;i=i+2)【改错3】【参考答案】printf(，，sum=%d\n/，,sum);。