Codeforces Round #109(Div.2) report

It is a long time to see you!

I have participated in Round #109 for the first time since Round #101. I think, this round is Readforces.

A: This problem is good for grammar practice. If you can max and min from array, you can solve this problem. I accepted this (it is only AC on this contest), 488pts.

B: When I submitted first, I forget array's initialization. Resubmit twice, the source passed pretest. However , it's RE on test 19.

D: I can say nothing about this problem... Submit, pretest passed and hacked!

ox-x-,1005th/1683,488pts, Rate:1578->1501. I remained in blue barely.

[A,AC (C)]

#include<stdio.h>

int main(void){
  int nowmax,nowmin,count=0,n,input;
  scanf("%d",&n);
  scanf("%d",&input);
  nowmax=nowmin=input;
  while(--n){
    scanf("%d",&input);
    if(nowmax<input){
      nowmax=input;
      count++;
    }else if(nowmin>input){
      nowmin=input;
      count++;
    }
  }
  printf("%d\n",count);
  return 0;
}


[B,RE (C)]

#include<stdio.h>
#include<stdlib.h>

int comp(const void *p1, const void *p2) {
  int n1, n2;
  n1 = *((const int *)p1);
  n2 = *((const int *)p2);
  return n2 - n1;
}

int main(void){
  unsigned int count=1,a,b,n,i=0,j,point=0;
  int num[1000];

  for(i=0;i<1000;i++) num[i]=0;

  i=0;

  scanf("%u",&n);
  while(n--){
    scanf("%u %u",&a,&b);
    if(b){
      count+=b-1;
      point+=a;
    }else{
      num[i++]=a;
    }
  }
  if(i!=0){
    qsort(num,sizeof(int)*i,sizeof(int),comp);
    for(j=0;j<count && j<i;j++) point+=num[j];
  }
  printf("%u\n",point);
  return 0;
}



[D,TLE (Hacked,C)]

#include<stdio.h>
#include<stdlib.h>

int rel_prime(int m,int n){
  if(n!=0) return rel_prime(n,m%n);
  else return m==1;
}

int main(void){
  int list[100000];
  int nowlist=0,m,n,i,j,k,flg;
  char *onoff;
  char in;
  int input;

  scanf("%d%*c%d%*c",&n,&m);
  onoff=(char *)calloc(n,sizeof(char));
  onoff--;
  while(m--){
    scanf("%c%*c%d%*c",&in,&input);
    if(in=='-'){
      if(onoff[input]){
for(i=0;i<nowlist;i++){
 if(list[i]!=input) continue;
 list[i]=0;
 onoff[input]=0;
 break;
}
puts("Success");
      }else{
puts("Already off");
      }
    }else if(in=='+'){
      if(onoff[input]){
puts("Already on");
      }else{
flg=1;
for(i=0;i<nowlist;i++){
 if(list[i]==0) continue;
 if((flg=rel_prime(input,list[i]))==0) break;
}
if(flg){
 onoff[input]=1;
 list[nowlist++]=input;
 puts("Success");
}else{
 printf("Conflict with %d\n",list[i]);
}
      }
    }
  }
  free(onoff+1);
  return 0;
}