Mon, 28 Oct 2019 16:23:22 +0800

nanjing/.vscode/settings.json

@@ -0,0 +1,49 @@
+{
+    "latex-workshop.intellisense.package.enabled": true,
+    "latex-workshop.latex.tools": [
+        {
+            "name": "xelatex",
+            "command": "xelatex",
+            "args": [
+                "-synctex=1",
+                "-interaction=nonstopmode",
+                "-file-line-error",
+                "%DOCFILE%"
+            ]
+        },
+        {
+            "name": "pdflatex",
+            "command": "pdflatex",
+            "args": [
+                "-synctex=1",
+                "-interaction=nonstopmode",
+                "-file-line-error",
+                "%DOCFILE%"
+            ]
+        },
+        {
+            "name": "bibtex",
+            "command": "bibtex",
+            "args": [
+                "%DOCFILE%"
+            ]
+        }
+    ],
+    "latex-workshop.latex.recipes": [
+        {
+            "name": "xelatex",
+            "tools": [
+                "xelatex"
+            ]
+        },
+        {
+            "name": "xe->bib->xe->xe",
+            "tools": [
+                "xelatex",
+                "bibtex",
+                "xelatex",
+                "xelatex"
+            ]
+        }
+    ],
+}

nanjing/main.tex

@@ -0,0 +1,216 @@
+\documentclass{ctexart}
+\usepackage{graphicx}
+\usepackage{amsmath}
+\usepackage{geometry}
+\usepackage{lmodern}
+\usepackage{fontspec}
+\usepackage{pdfpages}
+\usepackage{listings}
+\geometry{a4paper,scale=0.75}
+\pagestyle{empty}
+\begin{document}
+\includepdf[pages=-]{4.pdf}
+\includepdf[pages=-]{省选基础算法.pdf}
+\includepdf[pages=-]{1.pdf}
+\includepdf[pages=-]{2.pdf}
+\includepdf[pages=-]{3.pdf}
+\section*{hxd's debug list}
+\begin{quotation}
+    ACM本就逆风而行，在去机房的路上被风吹翻很正常。
+\end{quotation}
+\begin{itemize}
+    \item
+          线段树要开4倍内存
+    \item
+          cin跑得超级慢
+    \item
+          memset 比 for循环快得多
+          \begin{itemize}
+              \item
+                    memset总是清空整个数组，有时候只清理要用到的部分用for也许更好。
+          \end{itemize}
+    \item
+          有多组数据时要清空全局变量（以及各种队列）
+    \item
+          \texttt{std::accumulate} 的返回类型由第三个参数（初始值）决定。
+    \item
+          进bfs的时候要记得push初始状态。 / front后记得pop。
+    \item
+          检查输出编号是否在范围内(0)。
+    \item
+          检查不存在可行解时的输出(-1)。
+    \item
+          cin不仅跑得慢，而且跑得超级无敌螺旋飞天香蕉船慢。
+    \item
+          当你怎么样都过不了的时候（显然不会TLE的东西TLE了或者RE），试试把数组开大十倍，有可能是题面打错了。
+    \item
+          explicit specialization of 'template<class \_Tp> struct std::hash' outside its namespace must use a nested-name-specifier [-fpermissive].
+          for example: struct std::hash<pair<int, int> > but not struct hash<pair<int, int> >
+    \item
+          看题目数据范围，或许会出现$r-l \leq 2$这样的东西。
+\end{itemize}
+\includepdf[pages=-]{A_brief_introduction_to_pb_ds_for_ICPC.pdf}
+\includepdf[pages=-]{ICPC_Howtos_20190428.pdf}
+\section*{模拟退火}
+\begin{lstlisting}
+    #include <cmath>
+    #include <cstdio>
+    #include <cstdlib>
+    #include <ctime>
+    #include <iostream>
+    using namespace std;
+    
+    double y;
+    
+    double F(double x) {
+      return 6 * pow(x, 7) + 8 * pow(x, 6) 
+        + 7 * pow(x, 3) + 5 * pow(x, 2) - y * x;
+    }
+    
+    double Rand01() { return rand() / (double)RAND_MAX; }
+    
+    double Rand(double T) {
+      int f = rand() & 1;
+      return (f ? -1 : 1) * T * Rand01();
+    }
+    
+    int main() {
+      srand(time(NULL));
+      int Case;
+      scanf("%d", &Case);
+      while (Case--) {
+        scanf("%lf", &y);
+        double T = 100, T_end = 1e-6, d = 0.85, ans = F(0);
+        // T 初始温度，T_end 结束冷却温度，d 降温系数，ans 答案
+        double x_now = 0, x_next;
+        while (T > T_end) {
+          for (int i = 0; i < 2; i++) {
+            x_next = x_now + Rand(T);
+            //他手写的rand就是【-1,1】随机 取一个然后*t*（1 or -1）
+            if (x_next < 0 || x_next > 100)
+              continue;
+            //不科学就continue
+            double f_next = F(x_next), f_now = F(x_now);
+            //计算现在与之前的值
+            double delta = f_next - f_now; //计算差值
+    
+            cout << x_now << x_next << Rand01() << endl;
+    
+            if (delta < 0 || Rand01() < exp(-delta / T)) {
+              // delta<0表示下一个解比当前解更优哇
+              // （函数值更小）或者是概率接受记死exp（-delta/T）
+              x_now = x_next;         //修改啊哈哈
+              ans = min(ans, f_next); //题目要求最小x是ans
+            }
+          }
+          T *= d; //降温啦啦啦
+        }
+        printf("%.4f\n", ans);
+      }
+      return 0;
+    }
+\end{lstlisting}
+\begin{verbatim}
+    #include <bits/stdc++.h>
+    using namespace std;
+    const int maxn = 1e3 + 5;
+    const double inf = 1e80;
+    struct xd {
+      double a, b, c, d;
+    } xx[maxn];
+    int n;
+    double l;
+    
+    struct Point {
+      double x, y;
+    };
+    double dis(Point x, Point y) {
+      return sqrt((x.x - y.x) * (x.x - y.x) + (x.y - y.y) * (x.y - y.y));
+    }
+    double cos(double a, double b, double c) {
+      return (b * b + c * c - a * a) / (2 * b * c);
+    }
+    double dis(Point x, Point a, Point b) {
+      double l1 = dis(x, a);
+      double l2 = dis(x, b);
+      double l3 = dis(a, b);
+      if (cos(l1, l2, l3) < 0)
+        return l2;
+      if (cos(l2, l1, l3) < 0)
+        return l1;
+      double p = (l1 + l2 + l3) / 2;
+      double area = sqrt(p * (p - l1) * (p - l2) * (p - l3));
+      return area * 2 / l3;
+    }
+    double dis(double x, Point a, Point b) { return dis({x, 0}, a, b); }
+    
+    double f(double x) {
+      double mi = inf;
+      for (int i = 1; i <= n; i++) {
+        Point aa;
+        aa.x = xx[i].a, aa.y = xx[i].b;
+        Point bb;
+        bb.x = xx[i].c, bb.y = xx[i].d;
+        mi = min(mi, dis(x, aa, bb));
+      }
+      return mi;
+    }
+    
+    double rand01() { return rand() / (double)RAND_MAX; }
+    
+    double randnext(double T) {
+      int sgn = rand() & 1;
+      double haha = (sgn ? -1 : 1) * T * rand01();
+      return haha;
+    }
+    
+    int p[15];
+    int mls = 15;
+    
+    int main() {
+      int Tt;
+      scanf("%d", &Tt);
+      while (Tt--) {
+        srand(time(NULL));
+    
+        scanf("%d%lf", &n, &l);
+        for (int i = 1; i <= n; i++) {
+          scanf("%lf%lf%lf%lf", &xx[i].a, &xx[i].b, &xx[i].c, &xx[i].d);
+        }
+    
+        for (int i = 0; i < mls; i++)
+          p[i] = rand01() * l;
+    
+        double T = l, Tend = 1e-5, d = 0.95, ans = -1e100;
+        double id = 0;
+        double pos = 0;
+        while (T > Tend) {
+          for (int i = 0; i < mls; i++) {
+            double inmin = -1e100;
+            double pmin = p[i];
+            for (int i = 0; i < mls; i++) {
+              double add = randnext(T);
+              if (add + p[i] > l || add + p[i] < 0)
+                continue;
+              double tp = add + p[i];
+              double nexhi = f(tp);
+              double delta = inmin - nexhi;
+              if (delta < 0) {
+                pmin = tp;
+                inmin = nexhi;
+              }
+            }
+            p[i] = pmin;
+            if (inmin > ans) {
+              ans = inmin;
+              pos = pmin;
+            }
+          }
+          T *= d;
+        }
+        cerr << pos << endl;
+        printf("%.3lf\n", ans);
+      }
+    }
+\end{verbatim}
+\end{document}