yutao

level1/0runningLetter.c

@@ -0,0 +1,28 @@
+#include <stdio.h>
+#include <unistd.h>
+#define COLUMN 80 
+
+int main(){
+	int blank,location;
+
+	for (location = 1; location <=COLUMN ; location++){
+		for (blank=1; blank < location; blank++){
+			printf(" ");
+		}
+		putchar('A');
+		usleep(2000000);
+		system("clear");
+	}
+	for (location = location-1; location >=1; location--){
+		for (blank=1; blank < location; blank++){
+			printf(" ");
+		}
+		putchar('A');
+		usleep(200000);
+		system("clear");
+	}
+	return 0;
+}
+
+
+

level1/Diophantus.c

@@ -0,0 +1,12 @@
+#include <stdio.h>
+
+int main()
+{
+	int x;
+	for(x=1; x<150; x++){
+		if(x/6 + x/12 + x/7 + 5 + x/2 + 4 ==x)  
+			break;
+	}
+	printf("The father had lived for %d years.\n",x);
+	return 0;
+}

level1/allPrime.c

@@ -0,0 +1,22 @@
+#include <stdio.h>
+#include <math.h>
+#include <time.h>
+
+int main()
+{
+	int i,j; 
+	long begin,end;
+
+	begin = time(NULL);
+	printf("\nThe primes are:\n%-7d",2);
+	for (i=3; i<1000; i=i+2){
+		for (j=3; j<=(int)sqrt(i); j=j+2)
+			if (i%j == 0) break;
+		if (j > (int)sqrt(i) )  printf("%-7d",i);
+	}
+	end = time(NULL);
+	printf("\nThe begin time is: %d.",begin);
+	printf("\nThe end time is: %d.",end);
+	printf("\nThe total time is: %lf seconds.",(end-begin)/1000000.0);
+	return 0;
+}

level1/isPrime.c

@@ -0,0 +1,23 @@
+#include <stdio.h>
+#include <math.h>
+
+int main()
+{
+	int i,num;
+
+	printf("\nPlease enter a number: ");
+	scanf("%d",&num);
+	if (num == 2)
+		printf("\nIt's a prime.\n");
+	else{
+		for (i=2; i<=sqrt(num); i=i+2){
+			if (num % i==0){
+				printf("\nIt's not a prime.\n");
+				break;
+			}
+		}
+		if (i > sqrt(num))
+			printf("\nIt's a prime.\n");
+	}
+	return 0;
+}

level1/narcissus.c

@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+int main()
+{
+	int i,ones,tens,hundreds;
+	for (i=100; i<1000; i++){
+		ones = i % 10;
+		tens = i/10 %10;
+		hundreds = i/100;
+		if (ones*ones*ones + tens*tens*tens + hundreds*hundreds*hundreds == i)
+			printf("%7d\n",i);
+	}
+	return 0;
+}