完成作业2018081302016

level1/p01_runningLetter/runningletter.cpp

@@ -0,0 +1,20 @@
+#include <stdio.h>
+#include <windows.h>
+#include <math.h>
+#define len 80
+void blank(int i, int t){
+	int j;
+	for(;abs(i)!=t;i--){
+		for(j=0;j<=abs(i);j++){
+			printf(" ");
+		}
+		printf("H");
+		system("cls");
+	}
+}
+int main(){
+	blank(0, len);
+	blank(len, 0);
+	return 0;
+} 
+

level1/p02_isPrime/isPrime.cpp

@@ -0,0 +1,19 @@
+#include <stdio.h> 
+int main(){
+	int i, j, n;
+	j=0;
+	scanf("%d", &n);
+	for(i=2;i<n;i++){
+		if(n%i==0){
+			j++;
+		}
+
+	}
+	if(j==0){
+		printf("%d is a prime",n); 
+	}
+	else{
+		printf("%d is not a prime",n);
+	}
+	return 0;
+}

level1/p03_Diophantus/Diophantus.cpp

@@ -0,0 +1,13 @@
+#include <stdio.h> 
+int main(){
+	int i, t;
+	for(i=1;i<75;i++){
+		if(2*i%6==0 && 2*i%12==0 && 2*i%7==0){
+			if(i==2*i/6+2*i/12+2*i/7+9){
+				printf("when his son died, he is %d years old",2*i-4);
+			}
+		}
+	}
+	return 0;
+
+}

level1/p04_ narcissus/narcissus.cpp

@@ -0,0 +1,16 @@
+#include <stdio.h>
+int main(){
+	int i, j, k, a, b;
+	for(i=0;i<=9;i++){
+		for(j=0;j<=9;j++){
+			for(k=1;k<=9;k++){
+				a=k*100+j*10+i;
+				b=k*k*k+i*i*i+j*j*j;
+				if(a==b){
+					printf("%d ",a);
+				}
+			}
+		}
+	}
+	return 0;
+}

level1/p05_allPrimes/allPrime.cpp

@@ -0,0 +1,21 @@
+#include <stdio.h> 
+#include <time.h>
+int main(){
+	int i, j, t;
+	clock_t ts, te;
+	ts=clock();
+	for(i=2;i<=1000;i++){
+		t=0;
+		for(j=2;j<i;j++){
+			if(i%j==0){
+				t++;
+			}
+		}
+		if(t==0){
+			printf("%d \n",i);
+		}
+	}
+	te=clock();
+	printf("\n%d ms",te-ts);
+	return 0;
+}

level1/p06_Goldbach/Goldbach.cpp

@@ -0,0 +1,34 @@
+#include <stdio.h>
+#define range 100
+int isPrime(int num); 
+int main(){
+	int i, j, k, goldbach;
+	goldbach=0;
+	for(i=4;i<=range;i+=2){
+		for(j=2;j<=i/2;j++){
+			k=i-j;
+			if(isPrime(k) && isPrime(j)){
+				goldbach++;
+				break;
+			}
+		}
+	}
+	if(goldbach==range/2-1)
+		printf("%dis workable",range); 
+	else
+		printf("%d is not workable",range);
+	return 0;
+}
+int isPrime(int num){
+	int i, t;
+	t=0;
+	for(i=2;i<num;i++){
+		if(num%i==0){
+			t++;
+		}	
+	}
+	if(t==0)
+		return 1;
+	else
+		return 0;
+}

level1/p08_hanoi/hannoi1.cpp

@@ -0,0 +1,19 @@
+#include <stdio.h>
+#define N 64 
+void exchange(int n, char a, char b, char c) ;
+int main(){
+	exchange(N, 'a', 'b','c');
+
+}
+void exchange(int n, char a, char b, char c){
+	if(n==1){
+		printf("%c->%c\n", a, c);
+		//return;
+	}
+	else{
+		exchange(n-1, a, c, b);
+		printf("%c->%c\n",a, c);
+		exchange(n-1,b, a, c);
+
+	}
+}