寒假集训做题分享（4）
今天是习题课，讲了几道\(cf\) \(div2\) 的 \(B\) 题，挖去，全是思维题，少有的是直接模拟，用到算法不多，基本是贪心。pqy讲的太快了，看两眼就有思路了，我还读题理解题意呢，他结论出来了，这我还做牛魔题啊。。。
然后呢今天又做了几道上周学的计算几何，十分考验我的数学水平，但感觉最近做题频率比较高，消化不是很好，打算今天在学习学习上周讲的知识点，上周太难了。。。
题目列表：
1. Milena and Admirer
2. AB Flipping
3. P7934 [COCI2007-2008#5] JABUKE
4. Collecting Game
5. P1183 多边形的面积
6. P1257 平面上的最接近点对
7. Eat the Chip
8. P1496 火烧赤壁
1.
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
const int N = 1e6 + 100;
const int M = 1010;
int maxx = -1e18;
int minn = 1e18;
int cnt, sum;
int a[N];
signed main() {
int t;
cin >> t;
while (t--) {
int n, i;
cin >> n;
for (i = 1; i <= n; i++)
cin >> a[i];
int ans = 0;
minn = 1e18;
for (i = n; i >= 1; i--) {
if (a[i] <= minn) {
minn = min(minn, a[i]);
} else {
int t = (a[i] + minn - 1) / minn;
ans += t - 1;
minn = min(minn, a[i] / t);
}
}
cout << ans << endl;
}
}
2.
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
const int N = 1e6 + 100;
const int M = 1010;
int maxx = -1e18;
int minn = 1e18;
int cnt, sum;
bool v[N];
char s[N];
signed main() {
int t;
cin >> t;
while (t--) {
int n, i;
cin >> n;
scanf("%s", s + 1);
int ans = 0;
for (i = 1; i <= n; i++)
v[i] = 0;
for (i = n; i >= 1; i--) {
if (s[i] == 'A') {
int now = i;
while (!v[now] && s[now] == 'A' && s[now + 1] == 'B') {
v[now] = 1;
swap(s[now], s[now + 1]);
now++;
ans++;
}
}
}
cout << ans << endl;
}
}
3.
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
const int N = 1e6 + 100;
const int M = 1010;
int maxx = -1e18;
int minn = 1e18;
int cnt, sum;
signed main() {
double x1, x2, x3, y1, y2, y3;
cin >> x1 >> y1 >> x2 >> y2 >> x3 >> y3;
int n, i;
cin >> n;
double S = abs(x1 * (y2 - y3) + x2 * (y3 - y1) + x3 * (y1 - y2)) / 2;
for (i = 1; i <= n; i++) {
double x, y;
cin >> x >> y;
double S1 = abs(x * (y2 - y3) + x2 * (y3 - y) + x3 * (y - y2)) / 2;
double S2 = abs(x1 * (y - y3) + x * (y3 - y1) + x3 * (y1 - y)) / 2;
double S3 = abs(x1 * (y2 - y) + x2 * (y - y1) + x * (y1 - y2)) / 2;
if (S1 + S2 + S3 <=S)
cnt++;
}
printf("%.1lf\n%lld", S, cnt);
}
4.
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
const int N = 1e6 + 100;
const int M = 1010;
int maxx = -1e18;
int minn = 1e18;
int cnt, sum;
pair<int, int>a[N];
int q[N], ans[N];
signed main() {
int t;
cin >> t;
while (t--) {
int n;
cin >> n;
int i;
for (i = 1; i <= n; i++) {
scanf("%lld", &a[i].first);
a[i].second = i;
}
sort(a + 1, a + 1 + n);
for (i = 1; i <= n; i++) {
q[i] = q[i - 1] + a[i].first;
}
int r = 2;
for (i = 1; i <= n; i++) {
r = max(r, i + 1);
while (r <= n && q[r - 1] >= a[r].first) {
r++;
}
ans[a[i].second] = r - 2;
}
for (i = 1; i <= n; i++)
cout << ans[i] << " ";
cout << endl;
}
return 0;
}
5.
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
const int N = 1e6 + 100;
const int M = 1010;
int cnt, sum;
int x[N], y[N];
signed main() {
int n;
cin >> n;
int i;
for (i = 1; i <= n; i++) {
scanf("%lld %lld", &x[i], &y[i]);
}
x[n + 1] = x[1];
y[n + 1] = y[1];
for (i = 1; i <= n; i++) {
sum += (x[i] * y[i + 1] - x[i + 1] * y[i]);
}
cout << abs(sum / 2) << endl;
}
/*
--------
| |
| ---
| |
| |
------
*/
6.
#include<bits/stdc++.h>
using namespace std;
#define endl '\n'
#define int long long
const int N = 1e7 + 10;
const int M = 1010;
double maxx = -1e18;
double minn = 1e18;
int cnt;
//int a[M][M];
//bool p[M][M];
int x[N],y[N];
signed main() {
int n;
cin>>n;
int i,j;
for(i=1;i<=n;i++)
{
cin>>x[i]>>y[i];
for(j=i-1;j>=1;j--)
{
int aa=(x[i]-x[j])*(x[i]-x[j]);
int bb=(y[i]-y[j])*(y[i]-y[j]);
minn=min(sqrt(aa+bb),minn);
}
}
printf("%.4lf",minn);
}
7.
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
signed main() {
int t;
cin >> t;
while (t--) {
int n, m;
cin >> n >> m;
int ha, hb, la, lb;
cin >> ha >> la >> hb >> lb;
int ans = hb - ha;
if (ans <= 0) {
cout << "Draw" << endl;
continue;
}
int trun = ans / 2;
if (ans % 2 == 1) {
if (lb > la) {
la = min(la + trun + 1, m);
lb = min(lb + trun, m);
if (la >= lb)
cout << "Alice" << endl;
else
cout << "Draw" << endl;
} else {
int nnn = 1;
la = max(la - trun - 1, nnn);
lb = max(lb - trun, nnn);
if (la <= lb)
cout << "Alice" << endl;
else
cout << "Draw" << endl;
}
} else {
if (la > lb) {
la = min(la + trun, m);
lb = min(lb + trun, m);
if (la <= lb)
cout << "Bob" << endl;
else
cout << "Draw" << endl;
} else {
int nnn = 1;
la = max(la - trun, nnn);
lb = max(lb - trun, nnn);
if (la >= lb)
cout << "Bob" << endl;
else
cout << "Draw" << endl;
}
}
}
}
8.
#include<bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
double pi = acos(-1);
const int N = 1e6 + 100;
const int M = 1010;
int cnt, sum;
//int a[N];
int x[N], y[N];
vector<pair<int, int>>a;
signed main() {
int n;
cin >> n;
int i;
for (i = 1; i <= n; i++) {
cin >> x[i] >> y[i];
}
sort(x + 1, x + 1 + n);
sort(y + 1, y + 1 + n);
for (i = 1; i <= n; i++) {
sum += y[i] - x[i];
if (i != n) {
if (y[i] > x[i + 1])
sum -= y[i] - x[i + 1];
}
}
cout << sum << endl;
return 0;
}
