CODEWITHSUNDEEP
c++dictionarystlcontainers
sameer pradhan
sameer pradhan

Reputation: 334

map giving some ambiguous value

The output expected is "2a3b3c4d3l4z" but i'm getting:12a3b3c4d3l4z.

Why the extra "1" is coming in the output?

char ipstr[] = "aabbbcccddddzzzzlll";
    cout<<"size of string:"<<sizeof(ipstr)<<endl;
    num = 0;
    map<char, int> ms;
    for(int i = 0; i<sizeof(ipstr);i++){
        if(ipstr[i] == ipstr[i+1])
            num++;
        else{
            ms[ipstr[i]] = num+1;
            num = 0;
        }
    }

    for(auto it = ms.begin();it != ms.end();it++){
        cout<<it->second<<it->first;
    }
    cout<<endl;

Upvotes: 1

Views: 87

Answers (2)

Kirill Korolev
Kirill Korolev

Reputation: 1006

You evaluated your string length including '\0' character (it can be ambigious that string ends with this one). Then in a for loop you added '\0' to the map. But what does it mean to print null character. That's why you have 1 and a whitespace at the beginning.

char ipstr[] = "aabbbcccddddzzzzlll";
int n = strlen(ipstr);
cout << "size of string:" << n << endl;
int num = 0;
map<char, int> ms;

for (int i = 0; i < n - 1; i++) {
    if (ipstr[i] == ipstr[i + 1])
        num++;
    else {
        ms[ipstr[i]] = num + 1;
        num = 0;
    }
}

for (auto it = ms.begin(); it != ms.end(); it++) {
    cout << it->second << it->first;
}
cout << endl;

Upvotes: 2

Adrian W
Adrian W

Reputation: 5026

The extra 1 is the printout of the entry {'\0', 1} caused by taking the trailing '\0' into the loop. The \0 is not printable, therefore you see only 1.

Upvotes: 2

Related Questions