习题5

5.1 绝对值的输出

#include <stdio.h>#include <stdlib.h>int main(){    int x;    printf ("请输入一个实数 x:");    scanf ("%d",&x);    if (x>=0)    printf ("输出x的绝对值 %d\n",x);    else    printf ("输出x的绝对值 %d\n",x=-(x),x);    return 0;}

5.2 判断奇偶性

#include <stdio.h>#include <stdlib.h>int main(){   int x;   printf ("请输入任意一个整数x:");   scanf ("%d",&x);   if (x%2==0)   printf ("偶数");   else   printf ("奇数");    return 0;}

5.3 判断三角形是否构成

#include <stdio.h>#include <stdlib.h>int main(){   int a,b,c,s,p;   printf ("请输入任意三角形的三条边a,b,c:");   scanf ("%d%d%d",&a,&b,&c);   if (a+c>b && a+b>c && b+c>a)   p=(a+b+c)\2;   s=sqrt[p(p-a)(p-b)(p-c)];   printf ("能构成三角形 面积为s=%d\n"s);   else   printf ("不能构成三角形");    return 0;}

5.4 利息与本金合计

#include <stdio.h>#include <stdlib.h>int main(){   int n,b;   float h;   printf ("请输入本金b和期限n:");   scanf ("%d%d",&b,&n);   if (n==1)   {   h=b+b*0.0225;   printf ("利息与本金的合计h=%f\n",h);   }   if (n==2)   {   h=b+b*0.0243*n;   printf ("利息与本金的合计h=%f\n",h);   }   if (n==3)   {   h=b+b*0.027*n;   printf ("利息与本金的合计h=%f\n",h);   }   if (n>3 && n<=8)   {   h=b+b*0.0288*n;   printf ("利息与本金的合计h=%f\n",h);   }   if (n==8)   {   h=b+b*0.03*n;   printf ("利息与本金的合计h=%f\n",h);   }    return 0;}

5.5

#include <stdio.h>#include <stdlib.h>int main(){    int year,flag;    printf ("Enter year:");    scanf ("%d",&year);    if (year%4==0 && year%100!=0)    flag=1;    else    flag=0;    if (year%400==0)    printf ("%d is a leap year!\n",year);    else    printf ("%d is not a leap year !\n",year);  return 0;}

5.9

#include <stdio.h>#include <stdlib.h>int main(){    int score;    printf ("请输入分数score:");    scanf ("%d",&score);    if (score<=100 && score>=90)    printf ("A:");    if (score<90 && score>=80)    printf ("B:");    if (score<80 && score>=70)    printf ("C:");    if (score<70 && score>=60)    printf ("D:");    if (score<60 && score>=0)    printf ("E:");    return 0;}