陈小羽 homework

practices/c/level0/C0/1.c

@@ -0,0 +1,6 @@
+//测试一下git
+#include <stdio.h>
+int main(){
+	printf("Hello World I'm Chenxiaoyu\n");
+	return 0;
+}

practices/c/level0/C0/makefile

@@ -0,0 +1,2 @@
+main: 1.c
+	cc 1.c

practices/c/level0/C1/1.c

@@ -0,0 +1,17 @@
+#include <stdio.h>
+#include <string.h>
+char ans1[3][10] = {"正数","负数","0"};
+char ans2[2][10] = {"奇数","偶数"};
+char *ans[2];
+int sgn(int n){
+	if(n == 0) return 2;
+	return n > 0 ? 0 : 1;
+}
+int main(){
+	int n;
+	scanf(" %d",&n);
+	ans[0] = ans1[sgn(n)];
+	ans[1] = n % 2 ? ans2[0] : ans2[1];
+	printf("%s %s", ans[0], ans[1]);
+	return 0;
+}

practices/c/level0/C1/2.c

@@ -0,0 +1,7 @@
+#include <stdio.h>
+int main(){
+	int n; 
+	scanf(" %d", &n);
+	printf("%s\n",(n % 13 == 0 ? "YES" : "NO"));
+	return 0;
+}

practices/c/level0/C1/3.c

@@ -0,0 +1,8 @@
+#include <stdio.h>
+int main(){
+	int n; 
+	scanf(" %d",&n);
+	printf("%s\n",( n % 4 == 0 && n % 100 != 0) || (n % 400 == 0) ? "YES" : "NO");
+	return 0;
+}
+///算法来自百度

practices/c/level0/C1/makefile

@@ -0,0 +1,6 @@
+my1: 1.c
+	cc 1.c
+my2: 2.c
+	cc 2.c
+my3: 3.c
+	cc 3.c

practices/c/level1/p01_runningLetter/makefile

@@ -0,0 +1,2 @@
+main: my.c
+	cc -lcurses my.c -g -o my.c.out

practices/c/level1/p01_runningLetter/my.c

@@ -0,0 +1,24 @@
+//written on unix
+#include <stdio.h>
+#include <curses.h>
+void delay(){
+	for(int i = 1; i <= 50000000; i++);
+}
+int main(){
+	initscr();
+	int pos = 0,dir = 1;
+	while(1){
+		int col = COLS - 1;
+		mvaddch(0,pos,'R');
+		refresh();
+		delay();
+		if(pos == 0)
+			dir = 1;
+		if(pos == col)
+			dir = -1;
+		mvaddch(0,pos,' ');
+		pos += dir;
+	}
+	endwin();
+	return 0;
+}

practices/c/level1/p02_isPrime/makefile

@@ -0,0 +1,2 @@
+main: my.c
+	cc my.c -o my.c.out -g

practices/c/level1/p02_isPrime/my.c

@@ -0,0 +1,14 @@
+#include <string.h>
+#include <stdio.h>
+int main(){
+	int n; 
+	scanf("%d",&n);
+	int flag = 1;
+	for(int i = 2; i*i <= n; i++)
+		if(n % i == 0){
+			flag = 0;
+			break;
+		}
+	printf("%s\n",(flag == 1 ? "YES" : "NO"));
+	return 0;
+}

practices/c/level1/p03_Diophantus/my.c

@@ -0,0 +1,9 @@
+#include <stdio.h>
+int main(){
+	for(int i = 0; i <= 200; i+=7*12){
+		if(2 * ( (i - 4) - (i / 7 + i / 6 + i / 12 + 5)) == i){
+			printf("%d\n", i - 4);
+		}
+	}
+	return 0;
+}

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

@@ -0,0 +1,12 @@
+#include <stdio.h>
+int pow_3(int x){
+	return x * x * x;
+}
+int main(){
+	for(int i = 100; i <= 999; i++){
+		int cur = pow_3( i % 10 ) + pow_3( (i/10) % 10 ) + pow_3( i / 100 );
+		if(cur == i) 
+			printf("%d\n", i);
+	}
+	return 0;
+}

practices/c/level1/p05_allPrimes/my.c

@@ -0,0 +1,40 @@
+//#include <cstring>
+#include <cstdio>
+#include <sys/time.h>
+//#include <numeric>
+//#include <chrono>
+#define maxn 2005
+//using namespace std;
+int prime[maxn];
+int not_prime[maxn];
+int cnt_prime;
+void get_prime(){
+	for(int i = 2; i <= 2000; i++){
+		if(!not_prime[i]) prime[++cnt_prime] = i;
+		for(int j = 1; j <= cnt_prime; j++){
+			if(i * prime[j] > 2000) break;
+			not_prime[i * prime[j]] = 1;
+			if(i % prime[j] == 0) break;
+		}
+	}
+}
+void work(){
+	get_prime();
+	for(int i = 1; i <= cnt_prime; i++){
+		printf("%d ",prime[i]);
+	}
+	printf("\n");
+}
+int main(){
+	struct timeval start, end;
+	gettimeofday( &start, NULL );
+
+	work();
+
+	gettimeofday( &end, NULL );
+	float timeuse = 1e6 * (end.tv_sec - start.tv_sec) + end.tv_usec - start.tv_usec;
+	timeuse *= 1e-6;
+	printf("Total time: %f\n", timeuse);
+	return 0;
+
+}

practices/c/level1/p06_Goldbach/my.c

@@ -0,0 +1,33 @@
+#include <string.h>
+#include <stdio.h>
+#define maxn 105
+int prime[maxn];
+int not_prime[maxn];
+int cnt_prime;
+void get_prime(){
+	for(int i = 2; i <= 100; i++){
+		if(!not_prime[i]) prime[++cnt_prime] = i;
+		for(int j = 1; j <= cnt_prime; j++){
+			if(i * prime[j] > 100) break;
+			not_prime[i * prime[j]] = 1;
+			if(i % prime[j] == 0) break;
+		}
+	}
+}
+int main(){
+	get_prime();
+	int flag = 1;
+	for(int i = 4; i <= 100; i += 2){
+		int cur = 0;
+		for(int j = 2; j <= i-2; j++){
+			if(!not_prime[j] && !not_prime[i-j]){
+				cur = 1; break;
+			}
+		}
+		if(cur == 0){
+			flag = 0; break;
+		}
+	}
+	printf("%s\n", (flag == 1 ? "right" : "wrong") );
+	return 0;
+}

practices/c/level1/p07_encrypt_decrypt/my.c

@@ -0,0 +1,36 @@
+/* useage */
+/* whe you use encrypt, the program will return you a seed, and you should use the seed to decrypt the code */
+/* example:
+	   $./my.cpp.out encrypt abcde
+	   WXYZ[ 10
+	   $./my.cpp.out decrypt WXYZ[ 10
+	   abcde
+ */
+#include <string.h>
+#include <stdio.h>
+#include <time.h>
+#include <stdlib.h>
+void en(char s[]){
+	int len = strlen(s);
+	int now = rand() % 30;
+	for(int i = 0; i < len; i++){
+		printf("%c", (char) (s[i] - now));
+	}
+	printf(" %d%d\n", now/10,now%10);
+}
+void de(char s[],char ti[]){
+	int len = strlen(s);
+	int now = 10 * (ti[0] - '0') + ti[1] - '0';
+	for(int i = 0; i < len; i++){
+		printf("%c", (char) (s[i] + now) );
+	}
+	printf("\n");
+}
+int main(int argc,char *argv[]){
+	srand(time(NULL));
+	if(argv[1][0] == 'e') 
+		en(argv[2]);
+	else 
+		de(argv[2],argv[3]);
+	return 0;
+}

practices/c/level1/p08_hanoi/my.c

@@ -0,0 +1,18 @@
+//this program will print the solution of hanoi of n discs 
+#include <stdio.h>
+#include <string.h>
+void dfs(int num,int a,int b,int c){
+	if(num == 1){
+		printf("%d -> %d\n", a,c);
+		return;
+	}
+	dfs(num-1,a,c,b);
+	dfs(1,a,b,c);
+	dfs(num-1,b,a,c);
+}
+int main(){
+	int n;
+	scanf("%d",&n);
+	dfs(n,1,2,3);
+	return 0;
+}

practices/c/level1/p09_maze/makefile

@@ -0,0 +1,2 @@
+main: my.c
+	cc -lcurses -g -o my.c.out my.c

practices/c/level1/p09_maze/map1

@@ -0,0 +1,18 @@
+17 47
+###############################################
+###############################################
+####              $############################
+#### ######## ##############           ########
+#### ########           #### ######### ########
+#### #######  ############## #       # ########
+####    #### ############### # ##### # ########
+####### ####             ### #    @# # ########
+####### #### ######## ###### ####### # ########
+#######       ####### ######         # ########
+############# ####### ################ ########
+#####################                  ########
+##################### #########################
+#############         #########################
+###############################################
+###############################################
+###############################################

practices/c/level1/p09_maze/map2

@@ -0,0 +1,19 @@
+18 45
+#############################################
+############   #####       ##################
+############ ############# ##################
+############ ##          # ##################
+############ ## ########## #        #########
+############ ## #*   ##### ######## #########
+############ ## #### ##### #%     # #########
+############ ## #### ##### ### #### #########
+############ ## #    ##### ### #### #########
+############ ## #### ##### ### #### #########
+############### #### ##### ### #### #########
+#################### ##### ### #### #########
+######            *# ##### #     @# #########
+###### ############# ##### ######## #########
+###### #############%#####          #########
+###### ######################################
+######^######################################
+   #     #