c++ primer 第十一章习题
练习11.1 map下标是关键字，可以设定类型。vector下标是整数。 map的元素是pair， vector是一个单类型。
练习11.3 11.4
#include
#include 练习11.5 map是关键词对集合，set是关键词集合。映射关系用map，关键词是set。
练习11.6 set没有重复的关键字， list可以重复。set元素有序排列。
练习11.7
int main() {
map> family = {{"jackson",{}},{"wang",{}}};
family["jackson"].push_back("michael");
family["jackson"].push_back("david");
family["wang"].push_back("shi");
for(auto x : family)
cout << "family "<< x.first << " has "< 练习11.8 好处是set自动去重
int main() {
vector v = {"hello", "hello", "world"};
set s(v.begin(), v.end());
sort(v.begin(), v.end());
auto unique_end = unique(v.begin(), v.end());
v.erase(unique_end, v.end());
for(auto x : v)
cout << "vector: "<< x< 练习11.9
int main() {
map> mp;
string word;
int line;
while(cin>>word>>line) {
mp[word].push_back(line);
}
for(auto x : mp) {
cout << "word "<< x.first << " appears in ";
for_each(x.second.begin(), x.second.end(), [](int&a){cout << "line: "< 练习11.10
支持定义但不支持操作。实际不应该支持定义，应该是模板动态加载的问题。因为vector的迭代器定义了<操作而list的没有。
练习11.11
multiset bookStore(compareIsbn); 练习11.12
int main() {
vector> v;
string s;
int i;
while(cin>>s>>i) {
v.push_back({s,i});
}
for(auto x : v)
cout << x.first<<" "< 练习11.13 make_pair 自动判断类型并返回，且不会有歧义。
练习11.14
int main() {
map>> family = {{"jackson",{}},{"wang",{}}};
family["jackson"].push_back({"michael", "1999 1 1"});
family["jackson"].push_back({"david", "2000 1 1"});
family["wang"].push_back({"shi", "1988 12 2"});
for(auto x : family)
cout << "family "<< x.first << " has "< 练习11.15 vector
练习11.16
int main() {
map mp = {{"nihao",1}};
map::iterator iter = mp.begin();
iter->second = 2;
cout<first<<' '<second< 练习11.17 T F multiset不支持push_back T T
练习11.18 map
练习11.19 multiset
练习11.20
int main() {
map count;
string word;
while(cin >> word) {
if(ispunct(word.back()))
word = word.substr(0,word.size()-1);
transform(word.begin(), word.end(), word.begin(), ::tolower);
auto ret = count.insert({word, 1});
if(!ret.second)
++ret.first->second;
}
for(auto x : count)
cout << "word "<< x.first<<" appears "<< x.second<< " times."< 练习11.21 将word对应的value加一。
练习11.22 pair
练习11.23
int main() {
multimap family;
family.insert({"jackson","michael"});
family.insert({"jackson","david"});
family.insert({"wang","shi"});
for(auto x : family)
cout << "family "<< x.first << " has "< 练习11.24 insert({0,1})
练习11.25 报错
练习11.26 key_type mapped_type
练习11.27 计数用count 是否存在用find
练习11.28 map
练习11.29 第一个大于关键字的元素迭代器或者end 同上 空范围对的一个pair，可插入位置，即第一个大于k的位置。
练习11.30 返回的迭代器范围pair的第一个迭代器中的value值
练习11.31
int main() {
multimap authors;
authors.insert({"david","book1"});
authors.insert({"david","kbb1"});
authors.insert({"aang","222"});
auto iter = authors.find("david");
auto n = authors.count("david");
while(n--) {
authors.erase(iter++);
}
return 0;
} 练习11.32
int main() {
multimap authors;
authors.insert({"david","book1"});
authors.insert({"david","kbb1"});
authors.insert({"aang","222"});
auto iter = authors.begin();
while(iter != authors.end()) {
cout <first << " "<< iter->second< 练习11.34 不变
练习11.35 不会更新重复的规则，只会保留第一次出现的规则。
练习11.36 报错