Codeforces Educational Codeforces Round 54 (Rated for Div. 2)

A. Minimizing the String

[code]#include<cstdio>
#include<cstring>
int main(){
int n,i,f;
char s[200005];
scanf("%d%s",&n,s);
f=n-1;
for(int i=0;i<n-1;i++){
if(s[i]>s[i+1]){
f=i;
break;
}

}
for(int i=0;i<n;i++){
if(i==f)
continue;
else printf("%c",s[i]);
}
printf("\n");
}

B. Divisor Subtraction

[code]#include<cstdio>
int main(){
long long n;
scanf("%lld",&n);
for(long long i=2;i*i<=n;i++){
if(n%i==0){
printf("%lld\n",(n-i)/2+1);
return 0;
}
}
printf("1\n");
return 0;
}

C. Meme Problem

[code]#include<bits/stdc++.h>
#include<cmath>
using namespace std;
int main(){
int T;
scanf("%d",&T);
while(T--){
double d;
scanf("%lf",&d);
double D=d*d/4-d;
if(D<0){
printf("N\n");
}
else D=sqrt(D),printf("Y %.9lf %.9lf\n",d/2+D,d/2-D);
}
}