标签：des color font main put turn std return size
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【数据范围】
对于 40%的数据，2 ≤b≤ 1,000；
对于 60%的数据，2 ≤b≤ 50,000,000；
对于 100%的数据，2 ≤a, b≤ 2,000,000,000。
既然保证有解，那么肯定有$gcd(a, b) = 1$，用$exgcd$求出$ax+by = 1$的一组解，再求出$x$的最小正整数解。
1 //It is made by Awson on 2017.10.7 2 #include <map> 3 #include <set> 4 #include <cmath> 5 #include <ctime> 6 #include <queue> 7 #include <stack> 8 #include <vector> 9 #include <cstdio> 10 #include <string> 11 #include <cstdlib> 12 #include <cstring> 13 #include <iostream> 14 #include <algorithm> 15 #define LL long long 16 #define Max(a, b) ((a) > (b) ? (a) : (b)) 17 #define Min(a, b) ((a) < (b) ? (a) : (b)) 18 using namespace std; 19 20 LL a, b, x, y; 21 22 LL exgcd(LL a, LL b, LL &x, LL &y) { 23 if (b == 0) { 24 x = 1; y = 0; 25 return a; 26 } 27 LL c = exgcd(b, a%b, x, y); 28 LL t = x; 29 x = y; 30 y = t-a/b*y; 31 return c; 32 } 33 void work() { 34 scanf("%lld%lld", &a, &b); 35 LL gcd = exgcd(a, b, x, y); 36 printf("%lld\n", (x%b+b)%b); 37 } 38 int main() { 39 work(); 40 return 0; 41 }
标签：des color font main put turn std return size
原文地址：http://www.cnblogs.com/NaVi-Awson/p/7634959.html
