CodeForces 219C Color Stripe

时间:2023-03-09 03:47:18
CodeForces 219C Color Stripe
Color Stripe

Time Limit:2000MS     Memory Limit:262144KB     64bit IO Format:%I64d & %I64u

Description

A colored stripe is represented by a horizontal row of n square cells, each cell is pained one of k colors. Your task is to repaint the minimum number of cells so that no two neighbouring cells are of the same color. You can use any color from 1 to k to repaint the cells.

Input

The first input line contains two integers n and k (1 ≤ n ≤ 5·105; 2 ≤ k ≤ 26). The second line contains n uppercase English letters. Letter "A" stands for the first color, letter "B" stands for the second color and so on. The first k English letters may be used. Each letter represents the color of the corresponding cell of the stripe.

Output

Print a single integer — the required minimum number of repaintings. In the second line print any possible variant of the repainted stripe.

Sample Input

Input
6 3
ABBACC
Output
2
ABCACA
Input
3 2
BBB
Output
1
BAB
 #include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
int main()
{
int n,m;
char s[];
while(scanf("%d%d",&n,&m)!=EOF)
{
scanf("%s",s);
int i,ans=;
m+=;
if(n==)
{
cout<<ans<<endl<<s<<endl;
continue;
}
if(m==)
{
int l=,r=;
for(i=;i<n;i++)
if(i%==)
{
if(s[i]=='B') l++;
else r++;
}
else
{
if(s[i]=='A') l++;
else r++;
}
if(l<r)
{
cout<<l<<endl;
for(i=;i<n;i++)
if(i%==) cout<<'A';
else cout<<'B';
}
else
{
cout<<r<<endl;
for(i=;i<n;i++)
if(i%==) cout<<'B';
else cout<<'A';
}
cout<<endl;
continue;
}
s[n]='#';
for(i=;i<n;i++)
if(s[i]==s[i-])
{
ans++;
for(int j=;j<=m;j++)
if(j==s[i]||j==s[i+]) continue;
else
{
s[i]=j;
break;
}
}
s[n]='\0';
cout<<ans<<endl<<s<<endl; }
return ;
}