HDOJ 1260 ticket-优快云博客

本文探讨了一个利用动态规划解决购票时间最优化的问题。通过实例分析，阐述了如何通过状态转移方程实现最优解计算，并提供了AC代码作为实践指导。文中详细解释了基础动态规划思想及应用，适合对算法优化感兴趣的读者深入学习。

题意：给出n个数，第i个数表示买第i张票的时间，第二行有n-1个数，第i个表示买第i和i+1张票需要的时间，8点开始买票，求要到几点才能买完所有的票

链接：http://acm.hdu.edu.cn/showproblem.php?pid=1260

思路：基础dp，状态转移方程dp[i] = min ( dp[i-1] + num[i], dp[i-2] + sum[i] )，i表示买第i张票的最小花费

注意点：无

以下为AC代码：

Run ID	Submit Time	Judge Status	Pro.ID	Exe.Time	Exe.Memory	Code Len.	Language	Author
13674540	2015-05-11 22:46:33	Accepted	1260	0MS	1592K	3341 B	G++	luminous11

#include <iostream>
#include <cstdio>
#include <string>
#include <cstring>
#include <iostream>
#include <cstring>
#include <cstdio>
#include <string>
#include <vector>
#include <deque>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <cmath>
#include <ctime>
#include <cctype>
#include <climits>
#include <iomanip>
#include <cstdlib>
#include <algorithm>
//#include <unordered_map>
//#include <unordered_set>
#define ll long long
#define ull unsigned long long
#define all(x) (x).begin(), (x).end()
#define clr(a, v) memset( a , v , sizeof(a) )
#define pb push_back
#define RDI(a) scanf ( "%d", &a )
#define RDII(a, b) scanf ( "%d%d", &a, &b )
#define RDIII(a, b, c) scanf ( "%d%d%d", &a, &b, &c )
#define RS(s) scanf ( "%s", s )
#define PI(a) printf ( "%d", a )
#define PIL(a) printf ( "%d\n", a )
#define PII(a,b) printf ( "%d %d", a, b )
#define PIIL(a,b) printf ( "%d %d\n", a, b )
#define PIII(a,b,c) printf ( "%d %d %d", a, b, c )
#define PIIIL(a,b,c) printf ( "%d %d %d\n", a, b, c )
#define PL() printf ( "\n" )
#define PSL(s) printf ( "%s\n", s )
#define rep(i,m,n) for ( int i = m; i <  n; i ++ )
#define REP(i,m,n) for ( int i = m; i <= n; i ++ )
#define dep(i,m,n) for ( int i = m; i >  n; i -- )
#define DEP(i,m,n) for ( int i = m; i >= n; i -- )
#define repi(i,m,n,k) for ( int i = m; i <  n; i += k )
#define REPI(i,m,n,k) for ( int i = m; i <= n; i += k )
#define depi(i,m,n,k) for ( int i = m; i >  n; i += k )
#define DEPI(i,m,n,k) for ( int i = m; i >= n; i -= k )
#define READ(f) freopen(f, "r", stdin)
#define WRITE(f) freopen(f, "w", stdout)
using namespace std;
const double pi = acos(-1);
template <class T>
inline bool RD ( T &ret )
{
    char c;
    int sgn;
    if ( c = getchar(), c ==EOF )return 0; //EOF
    while ( c != '-' && ( c < '0' || c > '9' ) ) c = getchar();
    sgn = ( c == '-' ) ? -1 : 1;
    ret = ( c == '-' ) ? 0 : ( c - '0' );
    while ( c = getchar() , c >= '0' && c <= '9' ) ret = ret * 10 + ( c - '0' );
    ret *= sgn;
    return 1;
}
inline void PD ( int x )
{
    if ( x > 9 ) PD ( x / 10 );
    putchar ( x % 10 + '0' );
}
const double eps = 1e-10;
const int dir[4][2] = { 1,0, -1,0, 0,1, 0,-1 };
struct node{
    int x, y, cnt;
    node(){}
    node( int _x, int _y ) : x(_x), y(_y) {}
    node( int _x, int _y, int _cnt ) : x(_x), y(_y), cnt(_cnt) {}
};
int dp[2005];
int s[2005];
int d[2005];
int main()
{
    int ncase;
    RDI ( ncase );
    while ( ncase -- ){
        clr ( dp, 0x3f3f3f3f );
        clr ( s, 0 );
        clr ( d, 0 );
        int k;
        RDI ( k );
        REP ( i, 1, k ){
            RDI ( s[i] );
        }
        REP ( i, 2, k ){
            RDI ( d[i] );
        }
        dp[0] = 0;
        dp[1] = s[1];
        REP ( i, 2, k ){
            dp[i] = min ( dp[i-1] + s[i], dp[i-2] + d[i] );
        }
        int ans = dp[k];
        int H = 8;
        int M = 0;
        int S = 0;
        H += ( ans / 3600 );
        ans %= 3600;
        M += ( ans / 60 );
        ans %= 60;
        S += ( ans );
        int flag = 0;
        while ( H > 12 ){
            H -= 12;
            flag ^= 1;
        }
        printf ( "%02d:%02d:%02d %s\n", H, M, S, flag?"pm":"am" );
    }
    return 0;
}