数据结构习题集答案(c版)(清华大学 严蔚敏)

1.16

void print_descending(int x,int y,int z)//按从大到小顺序输出三个数

{

scanf("%d,%d,%d",&x,&y,&z);

if(xy; //<->为表示交换的双目运算符,以下同

if(yz;

if(xy; //冒泡排序

printf("%d %d %d",x,y,z);

}//print_descending

1.17

Status fib(int k,int m,int &f)//求k阶斐波那契序列的第m项的值f

{

int tempd;

if(k<2||m<0) return ERROR;

if(m

else if (m==k-1) f=1;

else

{

for(i=0;i<=k-2;i++) temp=0;

temp[k-1]=1; //初始化

for(i=k;i<=m;i++) //求出序列第k至第m个元素的值

{

sum=0;

for(j=i-k;j

temp=sum;

}

f=temp[m];

}

return OK;

}//fib

分析:通过保存已经计算出来的结果,此方法的时间复杂度仅为O(m^2).如果采用递归编程(大多数人都会首先想到递归方法),则时间复杂度将高达O(k^m).

1.18

typedef struct{

char *sport;

enum{male,female} gender;

char schoolname; //校名为'A','B','C','D'或'E'

char *result;

int score;

} resulttype;

typedef struct{

int malescore;

int femalescore;

int totalscore;

} scoretype;

void summary(resulttype result[ ])//求各校的男女总分和团体总分,假设结果已经储存在result[ ]数组中

{

scoretype score;

i=0;

while(result.sport!=NULL)

{

switch(result.schoolname)

{

case 'A':

score[ 0 ].totalscore+=result.score;

if(result.gender==0) score[ 0 ].malescore+=result.score;

else score[ 0 ].femalescore+=result.score;

break;

case 'B':

score.totalscore+=result.score;

if(result.gender==0) score.malescore+=result.score;

else score.femalescore+=result.score;

break;

……?……?……

}

i++；

}

for(i=0;i<5;i++)

{

printf("School %d:\n",i);

printf("Total score of male:%d\n",score.malescore);

printf("Total score of female:%d\n",score.femalescore);

printf("Total score of all:%d\n\n",score.totalscore);

}

}//summary

1.19

Status algo119(int a[ARRSIZE])//求i!*2^i序列的值且不超过maxint

{

last=1;

for(i=1;i<=ARRSIZE;i++)

{

a[i-1]=last*2*i;

if((a[i-1]/last)!=(2*i)) reurn OVERFLOW;

last=a[i-1];

return OK;

}

}//algo119

分析:当某一项的结果超过了maxint时,它除以前面一项的商会发生异常.

1.20

void polyvalue()

{

float ad;

float *p=a;

printf("Input number of terms:");

scanf("%d",&n);

printf("Input the %d coefficients from a0 to a%d:\n",n,n);

for(i=0;i<=n;i++) scanf("%f",p++);

printf("Input value of x:");

scanf("%f",&x);

p=a;xp=1;sum=0; //xp用于存放x的i次方

for(i=0;i<=n;i++)

{

sum+=xp*(*p++);

xp*=x;

}

printf("Value is:%f",sum);

}//polyvalue

2.10

Status DeleteK(SqList &a,int i,int k)//删除线性表a中第i个元素起的k个元素

{

if(i<1||k<0||i+k-1>a.length) return INFEASIBLE;

for(count=1;i+count-1<=a.length-k;count++) //注意循环结束的条件

a.elem[i+count-1]=a.elem[i+count+k-1];

a.length-=k;

return OK;

}//DeleteK

2.11

Status Insert_SqList(SqList &va,int x)//把x插入递增有序表va中

{

if(va.length+1>va.listsize) return ERROR;

va.length++;

for(i=va.length-1;va.elem>x&&i>=0;i--)

va.elem[i+1]=va.elem;

va.elem[i+1]=x;

return OK;

}//Insert_SqList

2.12

int ListComp(SqList A,SqList B)//比较字符表A和B,并用返回值表示结果,值为正,表示A>B;