再次尝试

practices/c/level1/p01_runningLetter/runningR.c

@@ -0,0 +1,24 @@
+#include<stdio.h>
+#include<windows.h>
+void main()
+{
+	int i,j;
+	for (i = 0;i < 80;i++){
+		Sleep(50);
+		system("cls");
+		for (j = 0;j < i - 1;j++) {
+			printf(" ");
+		}
+		printf("R");
+
+	}
+	for (i = 80;i >= 0;i--){
+		Sleep(50);
+		system("cls");
+		for (j = 0;j < i - 1;j++){
+			printf(" ");
+		}
+		printf("R");
+	}
+	return 0;
+}

practices/c/level1/p02_isPrime/isPrime.c

@@ -0,0 +1,36 @@
+#include<stdio.h>
+int main()
+
+{
+	long int i, j;
+	printf("Please input a number: \t");
+	scanf_s("%d", &i);
+	if (i == 2) {
+		printf("%d  is a Prime.", i);
+	}
+	else if (i == 1) {
+		printf("%d  is not a Prime.", i);
+	}
+	else
+	{
+		j = 2;
+		while (i > j)
+		{
+			if (i%j == 0)
+				break;
+
+			else
+			{
+				if (i == j + 1)
+				{
+					printf("%d  is a Prime.", i);
+					break;
+				}
+				j++;
+
+			}
+		}
+    if (i > j + 1)
+		printf("%d  is not a Prime.", i);
+	}
+}

practices/c/level1/p03_Diophantus/isPrime.c

@@ -0,0 +1,36 @@
+#include<stdio.h>
+int main()
+
+{
+	long int i, j;
+	printf("Please input a number: \t");
+	scanf_s("%d", &i);
+	if (i == 2) {
+		printf("%d  is a Prime.", i);
+	}
+	else if (i == 1) {
+		printf("%d  is not a Prime.", i);
+	}
+	else
+	{
+		j = 2;
+		while (i > j)
+		{
+			if (i%j == 0)
+				break;
+
+			else
+			{
+				if (i == j + 1)
+				{
+					printf("%d  is a Prime.", i);
+					break;
+				}
+				j++;
+
+			}
+		}
+    if (i > j + 1)
+		printf("%d  is not a Prime.", i);
+	}
+}

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

@@ -0,0 +1,16 @@
+#include<stdio.h>
+int main()
+{
+	int i,j,k,l;
+	for (i = 100;i < 1000;i++)
+	{
+		k = i % 10;
+		j = (i % 100) / 10;
+		l = i / 100;
+		if (i == (k*k*k) + (j*j*j) + (l*l*l))
+		{
+			printf("%5d", i);
+		}
+	}
+	return 0;
+}

practices/c/level1/p05_allPrimes/allPrimes.c

@@ -0,0 +1,33 @@
+#include<stdio.h>
+#include<time.h>
+int main()
+{
+	int j;
+	double time;
+	clock_t begin, end;
+	begin = clock();
+	printf("%5d", 2);
+	for (int num = 3;num <= 1000;num++){
+		j = 2;
+		while (num > j){
+			if (num%j == 0)
+				break;
+			else{
+				if (num == j + 1){
+					printf("%5d", num);
+					break;
+				}
+				j++;
+
+			}
+		}
+	}
+	end = clock();
+	time = (double)(end - begin)/ CLOCKS_PER_SEC;
+	printf("\n\n����ʱ��Ϊ%f��", time);
+}
+
+
+
+
+

practices/c/level1/p06_Goldbach/Godback.c

@@ -0,0 +1,32 @@
+#include<stdio.h>
+void main()
+{
+	int  t=1;
+	int c[101] = { 0 };
+	int prime[26];
+	for (int a = 2;a <= 10;a++){
+		if (c[a] == 0){
+			for (int b = 2 * a;b <= 100;b += a)
+				c[b] = 1;
+		}
+	}
+	for (int a = 2;a <= 100;a++){
+		if (c[a] == 0) {
+			prime[t] = a;
+			t += 1;
+		}
+	}
+	int m, n;
+	for (m = 1;m <= 50;m++){
+		n = 2 * m;
+		for (int p = 1;p <= 26;p++) {
+			for (int d = 1;d <= p;d++)
+				if (n == prime[p] + prime[d])
+					printf("%2d=%2d+%2d\t", n, prime[p], prime[d]);
+		}
+	}
+	printf("\n\n");
+	if (m = 50)printf("��ˣ���100���ڸ�°ͺղ�����ȷ��");
+	else printf("��ˣ���100���ڸ�°ͺղ��벻��ȷ��");
+}
+

practices/c/level1/p07_encrypt_decrypt/encrypt_decrypt.c

@@ -0,0 +1,54 @@
+#include<stdio.h>
+#include<stdlib.h>
+
+int main()
+{
+	int L = 5;
+	int i;
+	char k, ch;
+	char* p = (char*)malloc(sizeof(char) * L);
+	int count = 0;
+	printf("��ѡ����������ܻ��ǽ���:a������     b������\n");
+	k = getch();
+	if (k == 'a') {
+		printf("������������ܵ��ַ���: ");
+		do
+		{
+			ch = getchar();
+			count++;
+			if (count >= L) {
+				p = (char*)realloc(p, sizeof(char*) * (++L));
+			}
+			p[count - 1] = (char)((int)ch + 4);
+		} while (ch != '\n');
+		printf("��һ������%d���ַ�\n���ܺ������Ϊ��", count - 1);
+		for (i = 0;i < count;i++) {
+			printf("%c", p[i]);
+		}
+		free(p);
+	}
+
+
+	else if (k == 'b') {
+		printf("������������ܵ��ַ���: ");
+		do
+		{
+			ch = getchar();
+			count++;
+			if (count >= L) {
+				p = (char*)realloc(p, sizeof(char*) * (++L));
+			}
+			p[count - 1] = (char)((int)ch - 4);
+		} while (ch != '\n');
+		printf("��һ������%d���ַ�\n���ܺ������Ϊ��", count - 1);
+		for (i = 0;i < count;i++) {
+			printf("%c", p[i]);
+		}
+		free(p);
+	}
+	else {
+		printf("���������Ϣ����.");
+		return 0;
+	}
+}
+

practices/c/level1/p08_hanoi/hanoi.c

@@ -0,0 +1,23 @@
+#include<stdio.h>
+void han(int num, char a, char b, char c);
+
+int main()
+{
+	int num;
+	printf("�����������ƶ��ĺ�ŵ��Բ��������");
+	scanf_s("%d", &num);
+	printf("�ƶ�˳��Ϊ��\n");
+	han(num, 'a',' b',' c');
+}
+
+void han(int num, char a, char b, char c)
+{
+	if (num == 1) {
+		printf("%c�ƶ���%c\n", a, c);
+	}
+	else {
+		han(num - 1, 'a',' c', 'b');
+		printf("%c�ƶ���%c\n", a, c);
+		han(num - 1, 'b', 'a', 'c');
+		}
+}