1、1. 要求在屏幕上輸出下一行信息。Thisisacprogram.程序:#include<stdio.h>intmain()printf(“thisisacprogram.n”);return0;2. 求兩個(gè)整數(shù)之和。程序：#include<stdio.h>intmain()inta,b,sum;a=122;b=234;sum=a+b;printf(“sumis%dn”,sum);return0;3. 求兩個(gè)整數(shù)之間的較大者程序：#include<stdio.h>intmain()intmax(intx,inty);inta,b,c;scanf("

2、%d,%d",&a,&b);c=max(a,b);printf("max=%dn",c);return0;intmax(intx,inty)intz;if(x>y)z=x;elsez=y;return(z);有人用溫度計(jì)測(cè)量出華氏發(fā)表示的溫度(如69°F),今要求把她轉(zhuǎn)換成以攝氏法表示的溫度(如20C)。公式：c=5(f-32)/9.其中f代表華氏溫度，c代表攝氏溫度。程序：#include<stdio.h>intmain()floatf,c;f=64.0;c=(5.0/9)*(f-32);printf("f=

3、%fnc=%fn",f,c);return0;計(jì)算存款利息。有1000元，想存一年。有一下三種方法可選：(1)活期：年利率為r1；(2)一年定期：年利率為r2；(3)存兩次半年定期：年利率為r3。分別計(jì)算一年后按三種方法所得到的本息和。程序：#include<stdio.h>intmain()floatp0=1000,r1=0.0036,r2=0.0225,r3=0.0198,p1,p2,p3;p1=p0*(1+r1);p2=p0*(1+r2);p3二p0*(1+r3/2)*(1+r3/2);printf("p1=%fnp2=%fnp3=%fn",p1

4、,p2,p3);return0;給定一個(gè)大寫字母，要求以小寫字母輸出。程序：#include<stdio.h>intmain()charc1,c2;c1='A;c2=c1+32;printf(“cn”,c2);printf(“dn”,c2);return0;4. 給出三角形的三邊長(zhǎng)，求三角形的面積。公式：若給定三角形的三邊長(zhǎng)，且任意兩邊之長(zhǎng)大于第三邊則：area二其中s=(a+b+C)/2.程序：#include<stdio.h>#include<math.h>intmain()doublea,b,c,area;a=3.67;b=5.43;c=6.2

5、1;s=(a+b+c)/2;area=sqrt(s*(s-a)*(s-b)*(s-c);printf(“a=%ftb=%ftc=%fn”,a,b,c);printf(“area=%fn”,area);return0;b2-4ac>0.b2-4ac>0.5. 求ax2+bx+c=0方程的根。a,b,c由鍵盤輸入，設(shè)程序：#include<stdio.h>#include<math.h>intmain()doublea,b,c,disc,x1,x2,p,q;scanf(“%lf%lf%lf”,&a,&b,&c);disc=b*b-4*a*

6、c;if(disc<0)printf(“Thisquestionhasnorealrootsn”);elsep=-b/(2.0*a);q=sqrt(disc)/(2.0*a);x1=p+q;x2=p-q;printf(“x1=%7.2fnx2=%7.2fn”,x1,x2);return0;先后輸出BOY三個(gè)字符。程序：#include<stdio.h>intmain()chara='B',b='O',c='Y'putchar(a);putchar(b);putchar(c);putchar(n');return0;用三個(gè)

7、getchar函數(shù)先后向計(jì)算機(jī)輸入BOY三個(gè)字符，然后用putchar函數(shù)輸出。程序：#include<stdio.h>intmain()chara,b,c;a=getchar();b=getchar();c=getchar();putchar(a);putchar(b);putchar(c);putchar(n');return0;或#include<stdio.h>intmain()putchar(getchar();putchar(getchar();putchar(getchar();putchar(n');return0;用getchar函數(shù)從

8、鍵盤讀入一個(gè)大寫字母，把它轉(zhuǎn)換成小寫字母，然后用getchar函數(shù)輸出對(duì)應(yīng)的小寫字母。程序：#include<stdio.h>intmain()charc1,c2;c1=getchar();c2=c1+32;putchar(c2);putchar(n');return0;輸入兩個(gè)實(shí)數(shù)，按代數(shù)值由小到大的順序輸出這兩個(gè)數(shù)。(參照將兩個(gè)杯子中的水互換，必須借助第三個(gè)杯子)。程序：#include<stdio.h>intmain()floata,b,t;scanf(“%f,%f”,&a,&b);if(a>b)t=a;a=b;b=t;printf(

9、“%5.2f,%5.2fn”,a,b);return0;輸入a，b，c三個(gè)數(shù)，要求由小到大的順序輸出程序：#include<stdio.h>intmain()floata,b,c,t;scanf("%f,%f,%f",&a,&b,&c);if(a>b);t=a;a=b;b=t;if(a>c)t=a;a=c;c=t;if(b>c)t=b;b=c;c=t;printf("%5.2f,%5.2f,%5.2fn",a,b,c);return0;14輸入一個(gè)字符，判斷它是否為大寫字母，如果是，將它轉(zhuǎn)換成小寫字母

10、，如果不是，不轉(zhuǎn)換。然后輸出最后得到的字符程序：#include<stdio.h>intmain()charch;scanf(“%c”,&ch);ch=(ch>='A'&&ch<='Z')?(ch+32):ch;printf(“%cn”,ch);return0;或#include<stdio.h>intmain()charch;scanf("%c",&ch);if(ch>='A'&&ch<='Z')printf(&q

11、uot;%cn",ch+32);elseprintf("%cn",ch);return0;15.有一個(gè)函數(shù):y=編一程序。輸入一個(gè)x的值，要求輸出相應(yīng)的y值16.要求按照考試成績(jī)的等級(jí)輸出百分制分?jǐn)?shù)段，A等為85分程序：#include<stdio.h>intmain()intx,y;scanf("%d",&x);if(x<0)y=-1;elseif(x=0)y=0;elsey=1;printf("x=%dny=%dn",x,y);return0;以上，B等為70-84分。C等為60-69分，D等為

12、60分以下。成績(jī)的等級(jí)由鍵盤輸入。程序：#include<stdio.h>intmain()chargrade;scanf("%c",grade);printf("Youscore:n");switch(grade)case'A':printf("85100n");break;case'B':printf("7084n");break;case'C':printf("6069n");break;case'D':print

13、f("<60n");break;default:printf("enterdateerrorn");return0;寫一程序，判斷某一年是否為閏年。程序:#include<stdio.h>intmain()intleap,year;printf("pleaseenteryear:");scanf("%d",&year);if(year%4=0)if(year%100=0)if(year%400=0)leap=1;elseleap=0;elseleap=1;elseleap=0;if(lea

14、p)printf("%disaleapyearn",year);elseprintf("%disnotaleapyearn",year);return0;或#include<stdio.h>intmain()intleap,year;printf("pleaseenteryear:");scanf("%d",&year);if(year%4!=0)leap=0;elseif(year%100!=0)leap=1;elseif(year%400!=0)leap=0;elseleap=1;if(le

15、ap=1)printf("%disaleapyearn",year);elseprintf("%disnotaleapyearn",year);return0;或#include<stdio.h>intmain()intleap,year;printf("pleaseenteryear:");scanf("%d",&year);if(year%4=0&&year%100!=0)|(year%400=0)leap=1;elseleap=0;if(leap=1)printf(&quo

16、t;%disaleapyearn",year);elseprintf("%disnotaleapyearn",year);return0;求ax2+bx+c=0方程的根。a,b,c由鍵盤輸入。(完整版)程序：#include<stdio.h>#include<math.h>intmain()doublea,b,c,disc,x1,x2,x3,realpart,imagepart;scanf("%lf,%lf,%lf",&a,&b,&c);printf("Theequation"

17、);if(fabs(a)<=1e-6)printf("isnotaquadratic");elsedisc=b*b-4*a*c;if(fabs(disc)<=1e-6)equalequalrealprintf("hastworoots%8.4fn",-b/2*a);elseif(disc>1e-6)printf("hastwodistinctrootsn%8.4f,%8.4f",x1,x2);x1=(-b+sqrt(disc)/2*a;x2=(-b-sqrt(disc)/2*a;elserealpart=-b/2*a

18、;imagepart=sqrt(-disc)/2*a;printf("hastwocomplexroots:n");printf("%8.4f+%8.4fin",realpart,imagepart);printf("%8.4f-%8.4fin",realpart,imagepart);return0;/注釋：由于b*b-4*a*c(disc)是實(shí)數(shù)，而實(shí)數(shù)在計(jì)算和存儲(chǔ)時(shí)會(huì)有一些微小的誤差，因此不能直接進(jìn)行如下判斷：/“if(disc=0)",因?yàn)檫@樣可能出現(xiàn)本來是零的量，由于上述誤差而判別為不等于零而導(dǎo)致結(jié)果錯(cuò)誤，/所以采

19、取的辦法是判別disc的絕對(duì)值(fabs(disc)是否小于一個(gè)很小的數(shù)(例如：1e-6)。如果小于此數(shù)，則認(rèn)為disc=0.17. 給出一個(gè)不多出5位的正整數(shù)，要求：(1)：求出它是幾位數(shù);(2)：分別輸出每一位數(shù)字；(3)：按逆序輸出各位數(shù)字，例如原數(shù)為321，輸出123。程序：#include<stdio.h>intmain()intnum,indiv,ten,hundred,thousand,ten_thousand,place;printf("請(qǐng)輸入一個(gè)正整數(shù)(099999)：");scanf("%d",&num);if(n

20、um>9999)place=5;elseif(num>999)place=4;elseif(num>99)place=3;elseif(num>9)place=2;elseplace=1;printf("位數(shù)為:%dn",place);ten_thousand=num/10000;thousand=(num-ten_thousand*10000)/1000;hundred=(num-ten_thousand*10000-thousand*1000)/100;ten=(num-ten_thousand*10000-thousand*1000-hundred*100)/10;indiv=(num-ten_thousand*10000-thousand*1000-hundred*100-ten*10);printf("每一個(gè)數(shù)字分別為：");printf("%d,%d,%d,%d,%dn",ten_thousand,thousand,hundred,ten,indiv);switch(place)case5:printf("反序數(shù)字為：%d%d%d%d%dn",indiv,ten,hundred,thou