实验三

#include<stdio.h>
char score_to_grade(int score); 
int main(){
    int score;
    char grade;
    while(scanf("%d",&score)!=EOF){
        grade=score_to_grade(score);
        printf("分数:%d,等级：%c\n\n",score,grade);
    }
      return 0;
}

char score_to_grade(int score){
    char ans;
    
    switch(score/10){
        case 10:
        case 9: ans='A'; break;
        case 8: ans='B'; break;
        case 7: ans='C'; break;
        case 6: ans='D'; break;
        default: ans='E';
        
    }
      return ans;
}

问题1：功能：将整数分数转换为对应的等级数字

问题2：1.双引号赋值字符变量，类型错误；2.无break，无法实现分层目的

#include<stdio.h>
 int sum_digits(int n);
 int main(){
     int n;
     int ans;
     while(printf("Enter n:"),scanf("%d",&n)!=EOF){
         ans=sum_digits(n);
         printf("n=%d,ans=%d\n\n",n,ans);
     }
     return 0;
 }
 int sum_digits(int n){
     int ans=0;
     while(n!=0){
         ans+=n%10;
         n/=10;
     }
     return ans;
 }

问题1：计算一个整数的各位数字之和

问题2：能。递归：将问题分解成子问题；循环：循环逐位计算

#include<stdio.h>
int power(int x,int n);

int main(){
	int x,n;
	int ans;
	while(printf("Enter x and n:",scanf("%d%D",&x,&n))!=EOF){
		ans=power(x,n);
		printf("n=%d,ans=%d\n\n");
	}
	return 0;
}
 int power(int x,int n){
 	int t;
 	if(n==0)
 	 return 1;
 	else if(n%2)
 	  return x*power(x,n-1);
 	else{
 		t=power(x,n/2);
 		return t*t;
	 }
 }

　　

问题1：是递归函数，递归

问题2：是

#include<stdio.h>
int func(int n,int m);
int main(){
	int n,m;
	int ans;
	while(scanf("%d%d",&n,&m)!=EOF){
		ans=func(n,m);
		printf("n=%d,m=%d,ans=%d\n\n",n,m,ans);
	}
	return 0;
} 

int func(int n,int m){
	if(m<0||m>n)
	return 0;
	if(m==0||m==n)
	return 0;
	return func(n-1,m)+func(n-1,m-1);
	
}

　

#include<stdio.h>
int func(int n,int m);
int main(){
	int n,m;
	int ans;
	while(scanf("%d%d",&n,&m)!=EOF){
		ans=func(n,m);
		printf("n=%d,m=%d,ans=%d\n\n",n,m,ans);
	}
	return 0;
} 

int func(int n,int m){
	if(m<0||m>n)
	return 0;
	if(m==0||m==n)
	return 1;
	if(m>n-m)
	m=n-m;
	long long res=1;
	for(int i=1;i<=m;i++){
		res=res*(n-m+i)/i; 
	}
	return(int)res;
}

　　

 

　

 

#include<stdio.h>
int gcd_two(int x,int y);
int gcd(int a,int b,int c);
int main(){
	int a,b,c;
	int ans;
	while(scanf("%d%d%d",&a,&b,&c)!=EOF){
		ans=gcd(a,b,c);
		printf("最大公约数:%d\n\n",ans);
	}
	return 0;
}
int gcd_two(int x,int y){
	while(y!=0){
		int temp=x%y;
		x=y;
		y=temp; 
	}
	return x;
}

int gcd(int x,int y,int z){
	int temp=gcd_two(x,y);
	return gcd_two(temp,z);
	
}

　　

#include <stdio.h>
void printHead(int i, int n) {
    int thisN = i*2-1; 
    int spaceN = n-i; 
    for(int j=1; j<=spaceN; j++) printf("       ");
    for(int j=1; j<=thisN; j++) {
        printf(" O "); 
        printf("    "); 
    }
    for(int j=1; j<=spaceN; j++) printf("       ");
    printf("\n");
}
 
void printBody(int i, int n) {
    int thisN = i*2-1;
    int spaceN = n-i; 
    for(int j=1; j<=spaceN; j++) printf("       ");
    for(int j=1; j<=thisN; j++) {
        printf("<H>"); 
        printf("    "); 
    }
    for(int j=1; j<=spaceN; j++) printf("       ");
    printf("\n");
}
 
void printFoot(int i, int n) {
    int thisN = i*2-1; 
    int spaceN = n-i; 
    for(int j=1; j<=spaceN; j++) printf("       ");
    for(int j=1; j<=thisN; j++) {
        printf("I I"); 
        printf("    "); 
    }
    for(int j=1; j<=spaceN; j++) printf("       ");
    printf("\n");
}
 
void printCharman(int n) {
    for(int i=n; i>0; i--) {
        printHead(i,n);
        printBody(i,n);
        printFoot(i,n);
        printf("\n");
    }
}
 
int main() {
    int n;
    printf("Enter n:");
    scanf("%d", &n);
    printCharman(n);
    return 0;
}