T9 Spelling (https://code.google.com/codejam/contest/dashboard?c=351101#s=p2)

T9Spelling.cpp

#include<iostream>
#include<map>

using namespace std;

map<char, int> t9;

void solve() {
    char prev = -1, cur;
    
    while((cur = cin.get()) != '\n') {
        if (prev != -1 && t9[cur] % 10 == t9[prev] % 10)
            cout << ' ';
        
        cout << t9[cur];
        prev = cur;
    }
}

int main() {
    int freq[] = { 3, 3, 3, 3, 3, 4, 3, 4 };
    int key = 2, t = 1, N;
    char c = 'a';
    
    for (int i = 0; i < 8; ++i, ++key)
        for (int j = 1, code = key; j <= freq[i]; ++j, ++c, code = code * 10 + key)
            t9[c] = code;
    
    t9[' '] = 0;
    cin >> N; cin.get();
    
    while (t <= N)
        cout << "Case #" << t++ << ": ", solve(), cout << endl;
}