杭電1395 2^x mod n=1
1332 ワード
2^x mod n = 1
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 11642 Accepted Submission(s): 3625
Problem Description
Give a number n, find the minimum x(x>0) that satisfies 2^x mod n = 1.
Input
One positive integer on each line, the value of n.
Output
If the minimum x exists, print a line with 2^x mod n = 1.
Print 2^? mod n = 1 otherwise.
You should replace x and n with specific numbers.
Sample Input
Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 11642 Accepted Submission(s): 3625
Problem Description
Give a number n, find the minimum x(x>0) that satisfies 2^x mod n = 1.
Input
One positive integer on each line, the value of n.
Output
If the minimum x exists, print a line with 2^x mod n = 1.
Print 2^? mod n = 1 otherwise.
You should replace x and n with specific numbers.
Sample Input
2 5
Sample Output
2^? mod 2 = 1 2^4 mod 5 = 1// #includeint main() { int n; while(scanf("%d",&n)!=EOF) { if(n%2==0||n==1) printf("2^? mod %d = 1
",n); else { int k=1; __int64 i=2; while(1) { if(i%n==1) { printf("2^%d mod %d = 1
",k,n); break; } i=(i%n)<<1;// n k++; } } } return 0; }