level_1_p01.c to level_1_p06.c

practices/c/level1/p01_runningLetter/level_1_p01.c

@@ -0,0 +1,21 @@
+#include<stdio.h>
+#include<windows.h>
+main()
+{
+	for(int i=1;i<=50;i++){
+		for(int j=1;j<=i;j++){
+			printf(" ");
+		}
+		printf("R");
+		Sleep(10);
+		system("cls");
+	}
+	for(int i=50;i>=1;i--){
+		for(int j=i;j>=1;j--){
+			printf(" ");
+		}
+		printf("R");
+		Sleep(10);
+		system("cls");
+	}
+}

practices/c/level1/p02_isPrime/level_1_p02.c

@@ -0,0 +1,15 @@
+#include<stdio.h>
+main()
+{ 	
+	int a;
+	scanf("%d",&a);
+	if(a==1){
+		printf("非素数");}
+	for(int i=2;i<=a-1;i++){
+		if(a%i==0){
+			printf("非素数");
+			break;}
+		else
+			printf("素数"); 	
+	}
+}

practices/c/level1/p03_Diophantus/level_1_p03.c

@@ -0,0 +1,14 @@
+#include<stdio.h>
+main()
+{
+	int ageDio;int ageSon;
+	int i,j;
+	for(i=1;i<=100;i++)
+	  for(j=1;j<=100;j++){
+		   ageDio=12*i*7*j;
+		   ageSon=ageDio/2;
+		    if(ageSon==((ageDio-4)-(ageDio*11/28+5))){
+		 printf("%d",ageDio);
+		}
+	}
+}

practices/c/level1/p04_ narcissus/level_1_p04.c

@@ -0,0 +1,12 @@
+#include<stdio.h>
+
+main()
+{
+	for(int a=1;a<=9;a++)
+		for(int b=0;b<=9;b++)
+			for(int c=0;c<=9;c++){
+					if(100*a+10*b+c==a*a*a+b*b*b+c*c*c){
+						printf("%d\n",100*a+10*b+c);
+					}
+			}
+}

practices/c/level1/p05_allPrimes/level_1_p05.c

@@ -0,0 +1,25 @@
+#include<stdio.h>
+#include<time.h>
+
+int prime(int m)
+{	
+	for (int i=2;i*i<=m;i++){
+		if(m%i==0)
+		{return 0;}
+	}
+	return 1;
+}
+
+main()
+{		
+	double start,finish;
+	start=clock();
+	for(int i=2;i<=1000;i++){
+		if(prime(i)>0){
+		printf("%d\n",i);
+		}
+	}
+	finish=clock();
+	printf("\n");
+	printf("%f",finish-start);
+}

practices/c/level1/p06_Goldbach/level_1_p06.c

@@ -0,0 +1,31 @@
+#include<stdio.h> 
+
+int checkprime(int m)
+{	
+	for (int i=2;i*i<=m;i++){
+		if(m%i==0)
+		{return 0;}
+	}
+	return 1;
+}
+
+int main()
+{
+	int a;int prime[100];int control_1=0;
+
+	for(int i=2;i<=100;i++){
+		if(checkprime(i)==1){
+			prime[control_1]=i;
+			control_1++;
+		}
+
+	}
+	for(int i=2;i<=50;i++){
+		for(int j=0;j<=24;j++){
+				a=2*i-prime[j];
+				if(checkprime(a)==1){
+					printf("%d=%d+%d\n",2*i,a,prime[j]);break;
+				}	
+		}
+	}
+}

practices/c/level1/p07_encrypt_decrypt/level_1_p07.c

@@ -0,0 +1,16 @@
+#include<stdio.h>
+#include<string.h>
+main(){
+	char password[1000];
+
+	scanf("%s",password);
+	for(int i=0;i<strlen(password);i++){
+	  password[i]+=5;
+	}
+	printf("%s\n",password);
+
+	for(int i=0;i<strlen(password);i++){
+		password[i]-=5;
+	}
+	printf("%s\n",password);
+}

practices/c/level1/p08_hanoi/level_1_p08.c

@@ -0,0 +1,17 @@
+#include<stdio.h>
+void hanoi(int n,char a,char b,char c){
+	if(n==1){
+		printf("move plate %d from column %c to column %c\n",n,a,c);
+	} 
+	else{
+		hanoi(n-1,a,c,b);
+		printf("move plate %d from column %c to column %c\n",n,a,c);
+		hanoi(n-1,b,a,c);
+	}
+}
+
+main(){
+	int n;
+	scanf("%d",&n);
+	hanoi(n,'A','B','C');
+}