Created
February 4, 2013 02:47
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maxprime of codejom 2013
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| #include <stdio.h> | |
| #include <stdlib.h> | |
| #include <string.h> | |
| #include <math.h> | |
| #include <algorithm> | |
| #include <iostream> | |
| #include <map> | |
| #include <vector> | |
| using namespace std; | |
| long prime[5000000]; | |
| bool isPrime(long num) { | |
| if (num == 2) return true; | |
| for (int i = 2; i < sqrt(num) + 1; i++) { | |
| if (num%i == 0) { | |
| return false; | |
| } | |
| } | |
| return true; | |
| } | |
| void gen_prime() { | |
| long pnt = 0; | |
| for (long i = 2; i <= 1000500; i++) { | |
| if (isPrime(i)) { | |
| prime[pnt] = i; | |
| pnt++; | |
| } | |
| } | |
| } | |
| void solve_by_line(){ | |
| long num; | |
| scanf("%ld%*[\n]",&num); | |
| for (long i = 0; i <= 5000000; i++) { | |
| if (prime[i] == num) { | |
| printf("%ld\n", prime[i]); | |
| break; | |
| } | |
| else if (prime[i] > num) { | |
| printf("%ld\n", prime[i-1]); | |
| break; | |
| } | |
| } | |
| } | |
| int main(){ | |
| //File Name | |
| char filename[100] = "maxprime-4"; | |
| char file_in[100] = ""; | |
| char file_out[100] = ""; | |
| strcpy(file_in, filename); | |
| strcpy(file_out, filename); | |
| strcat(file_in, ".in"); | |
| strcat(file_out, ".out"); | |
| //File input | |
| freopen(file_in,"r",stdin); | |
| //File output | |
| freopen(file_out,"w",stdout); | |
| gen_prime(); | |
| int n; | |
| scanf("%d%*[\n]",&n); | |
| for(int i=1;i<=n;i++){ | |
| solve_by_line(); | |
| } | |
| } |
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