exgcd+min

8.16/A-Frog/main.cpp

@@ -1,14 +1,37 @@
-//weiwancheng
 #include <iostream>
 #include<cstdio>
 #include<algorithm>
 #include <cmath>
 #include <cstdlib>
 using namespace std;
-int x,y,m,n,l;
+long long exgcd(long long a,long long b,long long &x,long long &y)
+{
+	if(b==0)
+	{
+		//x,y没赋初值
+		x=1;
+		y=0;
+		return a;
+	}
+	long long ret=exgcd(b,a%b,x,y);
+	long long tmp=x;
+	x=y;
+	y=tmp-a/b*y;
+	return ret;
+}
 int main()
 {
-	scanf("%d",&x,&y,&m,&n,&l);
-	
+	long long x,y,m,n,l;
+	scanf("%lld%lld%lld%lld%lld",&x,&y,&m,&n,&l);//%lld没打
+	long long a=m-n,b=l,c=y-x;
+	if(a<0)//负值没处理好
+	{
+		a*=-1;
+		c*=-1;
+	}
+	long long x0,y0;
+	long long g=exgcd(a,b,x0,y0);
+	if(c%g!=0)printf("Impossible");//WA 罪魁祸首
+	else printf("%lld",(c/g*x0%(b/g)+b/g)%(b/g));//负值没处理好
 	return 0;
 }