BZOJ4045 : [Cerc2014] bricks

#include<cstdio>
#define N 100010
typedef long long ll;
int T,n,i,a
,b
,c[2],d[2],ans;ll x;char s[2];
int main(){
scanf("%d",&T);
while(T--){
scanf("%d",&n);
c[0]=c[1]=d[0]=d[1]=ans=0;
for(i=1;i<=n;i++)scanf("%d%s",&b[i],s),a[i]=s[0]=='B',c[a[i]=s[0]=='B']+=b[i];
if(!c[0]||!c[1]){printf("%d\n",c[0]+c[1]);continue;}
for(i=1;i<=n;i++){
x=(ll)c[a[i]]*d[a[i]^1]-(ll)d[a[i]]*c[a[i]^1];
if(x%c[a[i]^1]||x<=0||x/c[a[i]^1]>b[i])d[a[i]]+=b[i];
else ans++,d[a[i]]=b[i]-x/c[a[i]^1],d[a[i]^1]=0;
}
printf("%d\n",ans);
}
return 0;
}