Submission #1774204

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Source Code Expand

#include<cstdio>
#include<cstring>
using namespace std;
char str[800100];
int n,k;
void solve(){
	int p=1,dr=1;
	while(p>0&&p<=n){
		if(str[p]=='A'){
			str[p]='B';
			dr=-dr;
			p+=dr;
		}
		else{
			str[p]='A';
			p+=dr;
		}
	}
}
int main(){
	freopen("D.in","r",stdin);
	scanf("%d%d",&n,&k);
	scanf("%s",str+1);
	for(int i=n+1;i<=n*4;i++)
		str[i]='A'+((i-n)&1);
	if(k<=n*2){
		int res=0,p=1,cnt=0;
		for(int i=1;i<=k;i++){
			if(str[p]-'A'==((res+(cnt&1))&1))
				res^=1;
			else{
				cnt++,p++;
				res=0;
			}
		}
		for(int j=1;j<=n;j++){
			if(cnt&1) str[j]='A'+'B'-str[j+cnt];
			else str[j]=str[j+cnt];
		}
		if(res) solve();
	}
	else{
		int res=0,p=1,cnt=0;
		for(int i=1;i<=n*2;i++){
			if(str[p]-'A'==((res+(cnt&1))&1))
				res^=1;
			else{
				cnt++,p++;
				res=0;
			}
		}
		for(int j=1;j<=n;j++){
			if(cnt&1) str[j]='A'+'B'-str[j+cnt];
			else str[j]=str[j+cnt];
		}
		if(res) solve();
		k-=n*2;
		if((n&1)&&(k&1))
			str[1]='A'+'B'-str[1];
	}
	for(int i=1;i<=n;i++)
		printf("%c",str[i]);
	printf("\n");
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:21:27: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result]
  freopen("D.in","r",stdin);
                           ^
./Main.cpp:22:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&k);
                     ^
./Main.cpp:23:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s",str+1);
                   ^

Judge Result