Codeforces Round #296 (Div. 2)

许久未上过博客，正如许久没写过题目， 如今许多模板题都敲不来了，不禁想“论练题的重要性”，先把这几次cf补一下 。

总的来说，Codeforces Round #297 (Div. 2) 并不难（至少前4题） a手速， b，c stl， d小技巧

B. Error Correct System

/***Good Luck***/
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <algorithm>
#include <stack>
#include <map>
#include <queue>
#include <vector>
#include <set>
#include <functional>
#include <cmath>
#include <numeric>

#define ll long long
#define Zero(x)  memset((x),0, sizeof(x))
#define Neg(x) memset((x), -1, sizeof(x))
#define dg(x) cout << #x << " = " << x << endl;
#define pk(x)   push_back(x)
#define pii pair<int, int>
using namespace std;
int OK = 1;
int n;
string s, t;
map<pair<char, char>, int > mp, rmp;
int main(){
    //freopen("data.out", "w", stdout);
    //freopen("data.in", "r", stdin);
    //cin.sync_with_stdio(false);
    while(cin >> n){
        cin >> s >>t;
        mp.clear();
        rmp.clear();
        int ans = 0;
        for(int i = 0; i< n;++i){
            if(s[i] != t[i]){
                mp[make_pair(s[i], t[i])] = i + 1;
                rmp[make_pair(t[i], s[i])] = i + 1;
                ans++;
            }
        }
        auto mb = mp.begin(), rmb = rmp.begin();
        bool flag = false;
        int ansa, ansb;
        while(!mp.empty() && !rmp.empty()){
             mb = mp.begin();
        rmb = rmp.begin();
            if(mb->first.first == rmb->first.first){
                flag = true;
                ansa = mb->second;
                ansb = rmb->second;
            }

            if(mb->first > rmb->first) {
                rmp.erase(rmb);
            }else if(mb->first < rmb->first){
                mp.erase(mb);
            }else {
                ans -= 2;
                cout << ans << endl;
                cout << mb->second << " " << rmb->second << endl;
                return 0;
            }
        }
        if(flag){
            cout << --ans <<endl;;
            cout << ansa << " " << ansb <<endl;
        }else {
            cout << ans << endl;
            cout << "-1 -1" << endl;
        }

    }
}

C. Glass Carving

/***Good Luck***/
#define _CRT_SECURE_NO_WARNINGS
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <string>
#include <algorithm>
#include <stack>
#include <map>
#include <queue>
#include <vector>
#include <set>
#include <functional>
#include <cmath>
#include <numeric>

#define ll long long
#define Zero(x)  memset((x),0, sizeof(x))
#define Neg(x) memset((x), -1, sizeof(x))
#define dg(x) cout << #x << " = " << x << endl;
#define pk(x)   push_back(x)
#define pii pair<int, int>
using namespace std;
int OK = 1;
int  n, w, h;
int main(){
    //freopen("data.out", "w", stdout);
    //freopen("data.in", "r", stdin);
    cin.sync_with_stdio(false);
    cin >> w >> h >> n;
    string c;
    int line;
    map <int, pii> mpw, mph;
    multiset<int> sw, sh;
    mpw[0] = make_pair(0, w);
    sw.insert(w);
    mph[0] = make_pair(0, h);
    sh.insert(h);
    map <int, pii>::iterator it;
    multiset<int>::iterator it1;
    pair<int, pii> t;
    for (int i = 0; i < n; ++i){
        cin >> c >> line;
        if (c == "V"){
            it = mpw.lower_bound(line);
            --it;
            t = *it;

            mpw.erase(it);
            mpw[t.first] = make_pair(t.first, line);
            mpw[line] = make_pair(line, t.second.second);
            it1 = sw.find(t.second.second - t.second.first);
            sw.erase(it1);
            sw.insert(line - t.first);
            sw.insert(t.second.second - line);
        }
        else {
            it = mph.lower_bound(line);
            --it;
            t = *it;
            mph.erase(it);
            mph[t.first] = make_pair(t.first, line);
            mph[line] = make_pair(line, t.second.second);
            it1 = sh.find(t.second.second - t.second.first);
            sh.erase(it1);
            sh.insert(line - t.first);
            sh.insert(t.second.second - line);
        }
        cout << (ll)(*(sw.rbegin()))* (ll)(*(sh.rbegin())) << endl;
    }

}

D. Clique Problem

#include <vector>
#include <set>
#include <functional>
#include <cmath>
#include <numeric>

#define ll long long
#define Zero(x)  memset((x),0, sizeof(x))
#define Neg(x) memset((x), -1, sizeof(x))
#define dg(x) cout << #x << " = " << x
#define pk(x)   push_back(x)
using namespace std;
#define maxn 200001
#define mod 10007
#define eps 1e-9
const int inf=0x7fffffff;
struct node
{
    int x,y;
};

node a[maxn];
bool cmp(node aa,node bb)
{
    if(aa.x==bb.x)
        return aa.y<bb.y;
    return aa.x<bb.x;
}
int main()
{
    int n,aa,bb;
    cin>>n;
    for(int i=0;i<n;i++)
    {
        scanf("%d%d",&aa,&bb);
        a[i].x=aa+bb;
        a[i].y=aa-bb;
    }
    sort(a,a+n,cmp);
    int l=-inf;
    int ans=0;
    for(int i=0;i<n;i++)
    {
        if(a[i].y>=l)
        {
            l=a[i].x;
            ans++;
        }
    }
    cout<<ans<<endl;
}