标签：cin void generate ring std span next printf tween
Peter wants to generate some prime numbers for his cryptosystem. Help him! Your task is to generate all prime numbers between two given numbers!
The input begins with the number t of test cases in a single line (t<=10). In each of the next t lines there are two numbers m and n (1 <= m <= n <= 1000000000, n-m<=100000) separated by a space.
For every test case print all prime numbers p such that m <= p <= n, one number per line, test cases separated by an empty line.
1 #include<iostream> 2 #include<math.h> 3 #include<string> 4 5 6 using namespace std; 7 8 string s; 9 bool Isprime(int m)//is prime 10 { 11 if(m==1) 12 return false; 13 int i=(int)sqrt(m); 14 for(int j=2;j<=i;j++) 15 { 16 if(m%j==0) 17 return false; 18 } 19 return true; 20 } 21 22 void primegen(int i,int j)//prime genaerator 23 { 24 25 while(i<=j) 26 { 27 if(Isprime(i)) 28 { 29 char t[10]; 30 sprintf(t,"%d\n",i); 31 32 s=s+t; 33 } 34 i++; 35 } 36 s=s+"\n"; 37 } 38 int main() 39 { 40 s=""; 41 int k; 42 cin>>k; 43 int i1,i2; 44 while(k>0) 45 { 46 cin>>i1; 47 cin>>i2; 48 k--; 49 primegen(i1,i2); 50 } 51 cout<<s<<endl; 52 return 0; 53 }
2016-12-31 13:15:16
标签：cin void generate ring std span next printf tween
原文地址：http://www.cnblogs.com/geekvan/p/6239111.html
