BZOJ 1113: [Poi2008]海报PLA

1113: [Poi2008]海报PLA

Time Limit: 10 Sec  Memory Limit: 162 MB
Submit: 1025  Solved: 679
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Description

N个矩形,排成一排. 现在希望用尽量少的矩形海报Cover住它们.

Input

第一行给出数字N,代表有N个矩形.N在[1,250000] 下面N行,每行给出矩形的长与宽.其值在[1,1000000000]2 1/2 Postering

Output

最少数量的海报数.

Sample Input

5
1 2
1 3
2 2
2 5
1 4

Sample Output

4

HINT

 

Source

 

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分析

单调栈

代码

 /*<--- Opinion --->*/

    #define HEADER
    #define MYMATH
 // #define FILEIO
 // #define FSTREAM
 // #define FREOPEN
    #define FASTREAD
    #define SHORTNAME

 ///// HEADER FILE /////

 #ifdef HEADER

 #include <cmath>
 #include <string>
 #include <cstdio>
 #include <cstring>
 #include <cstdlib>
 #include <algorithm>

 #include <sstream>
 #include <fstream>
 #include <iostream>

 #include <set>
 #include <map>
 #include <list>
 #include <queue>
 #include <stack>
 #include <vector>
 #include <utility>
 #include <functional>

 #endif

 ///// SHORTNAME /////

 #ifdef SHORTNAME

 #define LL long long
 #define ll long long
 #define re register
 #define un unsigned
 #define rb re bool
 #define ri re int
 #define ui un int
 #define rl re LL
 #define ul un LL

 #define rep (x, y) for (ri i = x; i <= y; ++i)
 #define repi(x, y) for (ri i = x; i <= y; ++i)
 #define repj(x, y) for (ri j = x; j <= y; ++j)
 #define repk(x, y) for (ri k = x; k <= y; ++k)

 #define upto(x) for (ri i = 1; i <= x; ++i)
 #define dnto(x) for (ri i = x; i >= 1; --i)

 #define up(x) for (ri i = 1; i <= x; ++i)
 #define dn(x) for (ri i = x; i >= 1; --i)

 #define put(x)   printf("%lld ",  (LL)x)
 #define putln(x) printf("%lld\n", (LL)x)

 #endif

 ///// FASTREAD /////

 #ifdef FASTREAD

 const int FR_lim = ;

 char *FR_c;

 inline void fsetup(FILE *FR_file)
 {
     FR_c = new char[FR_lim];
     fread(FR_c, , FR_lim, FR_file);
 }

 template <class T>
 inline void fread(T &FR_num)
 {
     FR_num = ; rb FR_neg = ;

     while (*FR_c < '')
         if (*FR_c++ == '-')
             FR_neg ^= true;

     while (*FR_c >= '')
         FR_num = FR_num* + *FR_c++ - '';

     if(FR_neg)FR_num = -FR_num;
 }

 #endif

 ///// FILE I/O /////

 #ifdef FILEIO

 FILE *FIN = fopen("input.txt", "r");
 FILE *FOUT = fopen("output.txt", "w");

 #ifndef FSTREAM

 #define fin FIN
 #define fout FOUT

 #endif

 #endif

 ///// FSTREAM /////

 #ifdef FSTREAM

 std::ifstream fin("input.txt");
 std::ofstream fout("output.txt");

 #endif

 ///// MYMATH /////

 #ifdef MYMATH

 #define min(a, b) (a < b ? a : b)
 #define max(a, b) (a > b ? a : b)

 #define Min(a, b) a = min(a, b)
 #define Max(a, b) a = max(a, b)

 #define abs(x) (x < 0 ? -x : x)

 #define sqr(x) ((x)*(x))

 #endif

 ///// _MAIN_ /////

 void _main_(void);

 signed main(void)
 {

 #ifdef FREOPEN
     freopen("input.txt", "r", stdin);
     freopen("output.txt", "w", stdout);
 #endif

     _main_();

 #ifdef FILEIO
     fclose(FIN);
     fclose(FOUT);
 #endif

 #ifdef FREOPEN
     fclose(stdin);
     fclose(stdout);
 #endif

 #ifdef FSTREAM
     fin.close();
     fout.close();
 #endif

     return ;
 }

 /*<--- Main --->*/

 #define N 250005

 int n;
 int ans;
 int h[N];
 int stk[N];
 int tot = ;

 void _main_(void)
 {
     fsetup(stdin);

     fread(n);

     ri x;

     up(n)
     {
         fread(x); fread(x);
         while (tot && stk[tot] > x)--tot;
         if (tot && stk[tot] == x)++ans;
         stk[++tot] = x;
     }

     putln(n - ans);
 }

BZOJ_1113.cpp

好像那天特别高兴的样子，不知不觉就敲了个不明所以的模板， 补一份正常的代码。

 #include <bits/stdc++.h>
 signed main(void) {
     int n, tot = ;
     scanf("%d", &n);
     std::stack<int> stk;
     for (int i = ; i <= n; ++i) {
         int h; scanf("%*d%d", &h);
         while (!stk.empty() && h < stk.top())
             stk.pop();
         if (!stk.empty() && h == stk.top())
             ++tot;
         stk.push(h);
     }
     printf("%d\n", n - tot);
 }

BZOJ_1113.cpp

@Author: YouSiki