刘鑫宇 level 1 全部

level1 1.c

@@ -0,0 +1,29 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <windows.h>
+
+/* run this program using the console pauser or add your own getch, system("pause") or input loop */
+
+
+int main() {
+ system("mode con cols=80 lines=20");
+ int x=0,y=0,mark=0;
+ while(1)
+  {
+  	int i;
+   for(i=0;i<x;i++)
+  	printf(" ");
+  	printf("r");
+   (mark%2==0)?x++:x--;
+   if(x==0||x==80)
+     {
+     	 mark++;
+     }
+  	Sleep(30);
+  	system("cls");
+
+  }
+	system("pause");
+	return 0;
+}
+

level1 2.c

@@ -0,0 +1,24 @@
+#include <stdio.h>
+#include <stdlib.h>
+int main()
+{
+	int num,mark=0,i;
+	printf("����һ�����ڶ�������");
+	scanf("%d", &num);
+	for (i=2;i<num;i++)
+	{
+		if (num % i == 0)
+		{
+			printf("%d��������", num);
+			mark = 1;
+			break;
+		}
+	  }
+
+	if (mark == 0)
+	{
+		printf("%d������", num);
+	}
+		system("pause");
+		return 0;
+}

level1 3.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+#include <stdlib.h>
+int main()
+{
+	for (float i = 0; i < 100; i++)
+	{
+		float as_child = i / 6;
+		float as_tee = i / 12;
+		float live_alone = i / 7;
+		float get_son = 5;
+		float son_live = i / 2;
+		if (as_child + as_tee + live_alone + get_son + son_live + 4 == i)
+			printf("%f", i);
+	}
+	system("pause");
+    return 0;
+}

level1 4.c

@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include <stdlib.h>
+int main()
+{
+	int units, tens, hundreds;
+	for (int i = 100; i < 999; i++)
+	{
+		hundreds = i / 100;
+		tens = i / 10 %10;
+		units = i % 100 %10;
+		if (i == hundreds*hundreds*hundreds + tens*tens*tens + units*units*units)
+			printf("%d ", i);
+	}
+		system("pause");
+		return 0;
+}

level1 5.c

@@ -0,0 +1,26 @@
+#include<stdio.h>
+#include<stdlib.h>
+#include<time.h>
+#include<math.h>
+int main(){
+	printf("2 3 ");
+	double start, finish;
+	start = clock();
+	for (int j = 2; j <= 1000; j++)
+	for (int i = 2; i <= sqrt(j); i++)
+	{
+
+		if (j%i == 0)
+		{
+			break;
+		}
+		if (i == (int)sqrt(j))
+		{
+			printf("%d ",j);
+		}
+	}
+	finish = clock();
+	printf(" %f seconds\n", (finish - start) / CLOCKS_PER_SEC);
+	system("pause");
+	return 0;
+}

level1 6.c

@@ -0,0 +1,47 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+void Goldbach();
+
+int main()
+{	
+	Goldbach();
+	system("pause");
+	return 0;
+}
+
+void Goldbach() {
+	int mark_prime1 = 0, mark_prime2 = 0;
+	for (int i = 2; i <= 100; i = i + 2)
+		for (int j = 2; j < i; j++)
+		{
+			for (int k = 2; k <= sqrt(j); k++)
+			{
+				mark_prime1 = 0;
+				if (j%k == 0)
+				{
+					mark_prime1 = 1;
+					break;
+				}
+
+			}
+			if (mark_prime1 == 0)
+			{
+				int ano_pri = i - j;
+				for (int k = 2; k <= sqrt(ano_pri); k++)
+				{
+					mark_prime2 = 0;
+					if (ano_pri%k == 0)
+					{
+						mark_prime2 = 1;
+						break;
+					}
+				}
+				if (mark_prime2 == 0)
+				{
+					printf("%d+%d=%d ", j, ano_pri, i);
+				}
+
+			}
+		}
+}