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]){
+						//cout << j << " " << i-j << endl;
+						//printf("%d %d",i,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 +1,41 @@
+/* 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++){
+				//cout << (char)(s[i] - now);
+				printf("%c", (char) (s[i] - now));
+		}
+		//cout << " " << now << endl;
+		printf(" %d%d\n", now/10,now%10);
+		//cout << endl;
+}
+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++){
+				//cout << (char)(s[i] + now);
+				printf("%c", (char) (s[i] + now) );
+		}
+		//cout << endl;
+		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
+#############################################
+############   #####       ##################
+############ ############# ##################
+############ ##          # ##################
+############ ## ########## #        #########
+############ ## #*   ##### ######## #########
+############ ## #### ##### #%     # #########
+############ ## #### ##### ### #### #########
+############ ## #    ##### ### #### #########
+############ ## #### ##### ### #### #########
+############### #### ##### ### #### #########
+#################### ##### ### #### #########
+######            *# ##### #     @# #########
+###### ############# ##### ######## #########
+###### #############%#####          #########
+###### ######################################
+######^######################################
+   #     #