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practices/c/level0/c1panduanshu.c

@@ -0,0 +1,23 @@
+# include <stdio.h>
+
+int main()
+{
+	int input;
+	scanf("%d",&input);
+
+	if(input>0){
+		if(input%2==0){
+			printf("是正数而且是偶数\n");
+		}
+		else {
+			printf("是正数但不是偶数\n");
+		}
+	}
+	else if(input==0){
+		printf("既不是正数也不是负数\n");
+	}
+	else{
+		printf("是负数\n");
+	}
+	return 0;	
+}

practices/c/level0/helloworld.c

@@ -0,0 +1,8 @@
+# include <stdio.h>
+
+int main()
+{
+	printf("Hello World! I'm 李帅锋！\n");
+
+	return 0;
+}

practices/c/level1/p01_runningLetter/RunningLetter.c

@@ -0,0 +1,26 @@
+# include<stdio.h>
+# include<windows.h>
+
+int main()
+{
+	int i,j;
+	for(i=0;i<12;i++){
+		for(j=0;j<i;j++){
+			printf(" ");
+		}
+		Sleep(100);
+		printf("R");
+		system("cls");
+	}
+
+	for(i=12;i>0;i--){
+		for(j=0;j<i;j++){
+			printf(" ");
+		}
+		Sleep(100);
+		printf("R");
+		system("cls");
+	}
+
+	return 0;
+ } 

practices/c/level1/p01_runningLetter/p01

@@ -0,0 +1,26 @@
+# include<stdio.h>
+# include<windows.h>
+
+int main()
+{
+	int i,j;
+	for(i=0;i<12;i++){
+		for(j=0;j<i;j++){
+			printf(" ");
+		}
+		Sleep(100);
+		printf("R");
+		system("cls");
+	}
+
+	for(i=12;i>0;i--){
+		for(j=0;j<i;j++){
+			printf(" ");
+		}
+		Sleep(100);
+		printf("R");
+		system("cls");
+	}
+
+	return 0;
+ } 

practices/c/level1/p02_isPrime/isprime.c

@@ -0,0 +1,23 @@
+# include<stdio.h>
+
+int main()
+{
+	int i,x = 0;
+	int infox=-1;
+	scanf("%d",&x);
+
+	for( i=2;i<x;i++){
+		if(x%i==0){
+			infox++;
+		}
+	}
+
+	if(infox==-1){
+		printf("是素数\n");
+	}
+	else {
+		printf("不是素数\n");
+	}
+
+	return 0;
+}

practices/c/level1/p02_isPrime/p02-isPrime.c

@@ -0,0 +1,23 @@
+# include<stdio.h>
+
+int main()
+{
+	int i,x = 0;
+	int infox=-1;
+	scanf("%d",&x);
+
+	for( i=2;i<x;i++){
+		if(x%i==0){
+			infox++;
+		}
+	}
+
+	if(infox==-1){
+		printf("是素数\n");
+	}
+	else {
+		printf("不是素数\n");
+	}
+
+	return 0;
+}

practices/c/level1/p03_Diophantus/Diophantus.c

@@ -0,0 +1,12 @@
+#include <stdio.h> 
+
+int main(void)
+{
+	int age;
+	//  age/6+age/12+age/7+5 = age-age/2-4
+
+	age = 28*9/3;
+	printf("when diophantus's child dead,diophantus was ：%d years old.",age-4);
+
+	return  0;
+ } 

practices/c/level1/p04_ narcissus/narcissus.c

@@ -0,0 +1,23 @@
+#include <stdio.h> 
+# include<math.h>
+
+int main(void)
+{
+	int shuixianshu;
+	int baiwei,shiwei,gewei;
+
+	printf("三位水仙数如下：\n");
+
+	for(int i = 100;i<1000;i++){
+		baiwei = i/100;
+		shiwei = (i%100)/10;
+		gewei  = i%10;
+
+		if(i==pow(baiwei,3)+pow(shiwei,3)+pow(gewei,3)){
+			shuixianshu = i;
+			printf("%d\t",shuixianshu);
+		}
+	}
+
+	return  0;
+ } 

practices/c/level1/p04_ narcissus/p04 shuixianshu.c

@@ -0,0 +1,19 @@
+# include <stdio.h>
+# include <math.h>
+
+int main()
+{
+	int number = 153;
+
+	for(number=100;number<1000;number++){
+
+	int number1 = number/100;
+	int number2 = (number%100)/10; 
+	int number3 = number%10;
+		if(number==pow(number1,3)+pow(number2,3)+pow(number3,3)){
+			printf("%d\n",number);
+		}
+	}
+
+	return 0;
+ } 

practices/c/level1/p05_allPrimes/allPrimers.c

@@ -0,0 +1,44 @@
+#include <stdio.h> 
+#include<time.h>
+
+int isPrimer(int num);
+
+int main()
+{
+	clock_t start,finish;
+	start = clock();	
+	int primer;
+
+
+	for(int i = 2;i<=1000;i++){
+		primer = isPrimer(i);
+		if(primer){
+			printf("%d\n",i);
+		}
+	}
+
+	printf("the running time is:\t");
+	finish = clock();
+	double time = (double)(finish-start)*1000/CLOCKS_PER_SEC;
+	printf("%lf ms",time);
+
+	return  0;
+ } 
+
+ int isPrimer(int num){
+ 	int result = 0;
+ 	int cnt = 0;
+
+ 	for(int i = 2;i<=sqrt(num);i++){
+ 			if(num%i==0)  {
+ 				cnt++;
+ 				break;
+			 }
+		 }
+
+	if(cnt==0){
+	 	result = 1;
+	}
+
+	 return result;
+ }

practices/c/level1/p05_allPrimes/p05-allPrimes.c

@@ -0,0 +1,21 @@
+# include<stdio.h>
+
+
+int main()
+{
+	int num;
+	int fox = 0;
+	for(num=2;num<2000;num++){
+		for(int i=2;i<num;i++){
+			if(num%i==0){
+				fox++;
+			} 
+		}
+		if(fox==0){
+			printf("%d\n",num);
+		}
+		fox=0;
+	}
+
+	return 0;
+}

practices/c/level1/p06_Goldbach/Goldbach.c

@@ -0,0 +1,52 @@
+#include <stdio.h> 
+#include<time.h>
+
+int isPrimer(int num);
+
+int main()
+{	
+	int primer[25];
+ 	int cnt = 0;
+ 	for(int i = 2;i<100;i++){
+	 	if(isPrimer(i))	{
+	 		primer[cnt] = i;
+	 		cnt++;
+		 }
+	 }
+
+	 for(int i=3;i<=100;i++){
+	 	if(i%2==0){
+	 		for(int m = 0;m<=25;m++){
+	 			for(int n = 0;n<=25;n++){
+	 				if(primer[m]+primer[n]==i){
+	 					printf("%d=%d+%d\n",i,primer[m],primer[n]);
+					 }
+				 }
+			 }
+		 }
+	 }
+
+ 	printf("So,we can learn that Goldbach's suspect is right in 0-100.\n");
+	return  0;
+ } 
+
+ int isPrimer(int num){
+ 	int result = 0;
+ 	int cnt = 0;
+
+ 	for(int i = 2;i<=sqrt(num);i++){
+ 			if(num%i==0)  {
+ 				cnt++;
+ 				break;
+			 }
+		 }
+
+	if(cnt==0){
+	 	result = 1;
+	}
+
+	 return result;
+ }
+
+
+

practices/c/level1/p08_hanoi/hanoi.c

@@ -0,0 +1,28 @@
+# include<stdio.h>
+
+int i= 0;
+
+int main()
+{
+	int N;
+	printf("input positive integer N: ");
+	scanf("%d",&N);
+
+	move('a','b','c',N);
+
+	printf("these are all steps!");
+	return 0;
+ } 
+
+ void move(char str1,char str2,char str3,int n)
+ {
+ 	if(n==1){
+ 		printf("the %dst step:\t",++i);
+ 		printf("%c->%c\n",str1,str3); 
+	 }else{
+	 	move(str1,str3,str2,n-1);
+	 	printf("the %dst step:\t",++i);
+	 	printf("%c->%c\n",str1,str3);
+	 	move(str2,str1,str3,n-1);
+	 }
+ }