C++ :

#include <cstdio>
#include <vector>
#include <string>
#include <map>
using namespace std;
/* 按用户名首次出现顺序输出，每个用户后面按记录顺序跟其浏览过的网页。 */
static char bu[1005], bp[1005];
int main(){
    int N, M;
    if(scanf("%d %d", &N, &M) != 2) return 0;
    map<string, int> id;
    vector<string> order;
    vector<vector<string> > pages;
    for(int i = 0; i < M; i++){
        scanf("%s %s", bu, bp);
        string u(bu), p(bp);
        map<string, int>::iterator it = id.find(u);
        int k;
        if(it == id.end()){ k = (int)order.size(); id[u] = k; order.push_back(u); pages.push_back(vector<string>()); }
        else k = it->second;
        pages[k].push_back(p);
    }
    for(size_t i = 0; i < order.size(); i++){
        printf("%s", order[i].c_str());
        for(size_t j = 0; j < pages[i].size(); j++) printf(" %s", pages[i][j].c_str());
        putchar('\n');
    }
    return 0;
}