#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#define maxn 200001
long long holy_shit[maxn],naga_siren[maxn],farm_roshan[maxn],billzard_cannon[maxn];
long long n,ans,cD_zhou_YY,c,ice_frog;
bool flag=false;
long long first_blood(long long a,long long b,long long &x,long long &y){
  if(b==0)
    return x=1,y=0,a;
  long long res=first_blood(b,a%b,x,y);
  long long t=x;
  x=y,y=t-(a/b)*y;
  return res;
}
long long rampage(long long a,long long b,long long n){
  long long d,x,y,e;
  d=first_blood(a,n,x,y);
  if(b%d!=0)
    return -1;
  e=x*(b/d)%n;
  return (e+n)%n;
}
long long wicked_sick(long long a,long long b){
  long long ans,x,y;
  ans=first_blood(a,b,x,y);
  return (a/ans)*b;
}
int main(){
  for(;scanf("%I64d",&n)!=EOF;ans=1,flag=false,ice_frog=0){
    for(int i=1;i<=n;i++)
      scanf("%I64d%I64d",&holy_shit[i],&naga_siren[i]);
    farm_roshan[1]=naga_siren[1],billzard_cannon[1]=holy_shit[1];
    for(int i=2;i<=n;i++){
      ice_frog=rampage(billzard_cannon[i-1],naga_siren[i]-farm_roshan[i-1],holy_shit[i]);
      if(ice_frog+1==0){
        flag=true;
        continue;
      }
      cD_zhou_YY=wicked_sick(billzard_cannon[i-1],holy_shit[i]);
      c=farm_roshan[i-1]+billzard_cannon[i-1]*ice_frog;
      farm_roshan[i]=c,billzard_cannon[i]=cD_zhou_YY;
    }
    printf("%I64d\n",((flag)?(-1):((c+cD_zhou_YY)%cD_zhou_YY)));
  }
  return 0;
}

• 确实够娱乐, 是写完代码替换的, 还是直接起的这些变量名? (1532) deitytoday 2011-08-22 16:48:51