PTA甲级
1082 Read Number in Chinese
字符串处理，恶心
#include<iostream>
#include<algorithm>using namespace std;string num[10] = {"ling" , "yi" , "er" , "san" , "si", "wu" , "liu" , "qi" , "ba" , "jiu"};
string pos[10] = {"" , "Shi" , "Bai" , "Qian" , "Wan" ,"Shi", "Bai", "Qian" , "Yi"};
string s;
bool f = false;int main()
{cin >> s;if(s[0] == '-') f = true , s.erase(0 , 1);int zeros = 0; // 两个以上的要读为0string res;for(int i = 1;i <= s.size();i ++){int now = s[i - 1] - '0';if(now) // 非零{if(zeros) res += " ling" , zeros = 0;if(i > 1) res += " ";res += num[now] + " " + pos[s.size() - i];}else{zeros ++;if((s.size() - i) % 4 == 0 && zeros % 4) res += " " + pos[s.size() - i] , zeros = 0;}}res.pop_back();if(f) cout << "Fu ";if(s != "0") cout << res << endl;else cout << "ling" << endl;return 0;
}1086 Tree Traversals Again
已知中序和前序，求后序
#include<iostream>
#include<stack>
#include<vector>using namespace std;const int N = 50;
int n;
stack<int>st;
int in[N] , pre[N] , pos[N];
int l[N] , r[N];
vector<int>post;int build(int il , int ir , int pl , int pr)
{int root = pre[pl];int k = pos[root];if(il < k) l[root] = build(il , k - 1 , pl + 1 , pl + k - il);if(k < ir) r[root] = build(k + 1 , ir , pl + k - il + 1 , pr);post.push_back(root);return root;
}int main()
{cin >> n;n *= 2;int cnt = 0 , cnti = 0;while(n --){string s;int x;cin >> s;if(s == "Push") cin >> x , st.push(x) , pre[cnt ++] = x;else in[cnti] = st.top() , pos[st.top()] = cnti ++ , st.pop();}n = cnt;build(0 , n - 1 , 0 , n - 1);for(int i = 0;i < post.size();i ++){if(i) cout << " ";cout << post[i];}return 0;
}1087 All Roads Lead to Rome
迪杰斯特拉
#include<iostream>
#include<vector>
#include<cstring>
#include<unordered_map>
#include<algorithm>using namespace std;const int N = 510;
int n , m;
string start;
unordered_map<string , int>mp;
unordered_map<int , string>rev_mp;
int happy[N];
int g[N][N];
bool st[N];
int dist[N] , path[N] , cnt[N] , ha[N];
int point[N];void dij()
{memset(st , 0 , sizeof st);memset(dist , 0x3f , sizeof dist);memset(path , -1 , sizeof path);dist[mp[start]] = 0, cnt[mp[start]] = 1 , point[mp[start]] = 1 , ha[mp[start]] = happy[mp[start]];for(int i = 1;i <= n;i ++){int t = -1;for(int j = 1;j <= n;j ++)if(!st[j] && (t == -1 || dist[t] > dist[j]))t = j;st[t] = true;for(int j = 1;j <= n;j ++){if(dist[j] > dist[t] + g[t][j]){dist[j] = dist[t] + g[t][j];cnt[j] = cnt[t];ha[j] = ha[t] + happy[j];path[j] = t;point[j] = point[t] + 1;}else if(dist[j] == dist[t] + g[t][j]){cnt[j] += cnt[t];if(ha[j] < ha[t] + happy[j]) {ha[j] = ha[t] + happy[j];path[j] = t;point[j] = point[t] + 1;}else if(ha[j] == ha[t] + happy[j]) {if(point[j] > point[t] + 1){path[j] = t;point[j] = point[t] + 1;}}}}}
}int main()
{memset(g , 0x3f , sizeof g);cin >> n >> m >> start;for(int i = 0;i < n - 1;i ++){string s;int h;cin >> s >> h;mp[s] = i + 1;rev_mp[i + 1] = s;happy[i + 1] = h;}mp[start] = n;rev_mp[n] = start;while(m --){string a , b;int c;cin >> a >> b >> c;g[mp[a]][mp[b]] = g[mp[b]][mp[a]] = c;}dij();cout << cnt[mp["ROM"]] << " " << dist[mp["ROM"]] << " ";cout << ha[mp["ROM"]] << " ";vector<int>res;for(int i = mp["ROM"];~i;i = path[i])res.push_back(i);cout << ha[mp["ROM"]] / (res.size() - 1) << endl;reverse(res.begin() , res.end());for(int i = 0;i < res.size();i ++){if(i) cout << "->";cout << rev_mp[res[i]];}return 0;
}
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