Encoding and Decoding

EPI 7.12

Description:

Example:

encoding:
"aaabbdc" -> 3a2b1d1c

decoding:
1b3c2a -> bcccaa

Idea:

Code要写清楚。

Code:

#include <iostream>
#include <vector>
#include <string>
#include <algorithm>

using namespace std;

int findNextChar(const string& input, int i){
    char a=input[i];
    int j=i;
    for(; j<input.size(); ++j){
        if(input[j] != input[i])
            break;
    }
    return j;
}

string encoding(string input){
    string result;
    int i=0;
    int j=0;
    while(i<input.size()){
        j = findNextChar(input, i);
        result.push_back(j-i+'0');
        result.push_back(input[i]);
        i=j;
    }
    return result;
}

string decoding(string input){
    string result;
    int count=0;
    for(int i=0; i<input.size(); i++){
        if(isdigit(input[i])){
            count = input[i]-'0';
        }
        else{
            result.append(count, input[i]);
        }
    }
    return result;
}

int main(){
    cout<<encoding("aaabbdc")<<endl;
    cout<<decoding("1b3c2a")<<endl;
}