SOJ 2013年每周一赛第⑨场 D

	1003. Bookshelf
	Time Limit: 1sec    Memory Limit:256MB Description When Farmer John isn't milking cows, stacking haybales, lining up his cows, or building fences, he enjoys sitting down with a good book. Over the years, he has collected N books (1 <= N <= 2,000), and he wants to build a new set of bookshelves to hold them all. Each book i has a width W(i) and height H(i). The books need to be added to a set of shelves in order; for example, the first shelf should contain books 1...k for some k, the second shelf should start with book k+1, and so on. Each shelf can have a total width of at most L (1 <= L <= 1,000,000,000). The height of a shelf is equal to the height of the tallest book on that shelf, and the height of the entire set of bookshelves is the sum of the heights of all the individual shelves, since they are all stacked vertically. Please help FJ compute the minimum possible height for the entire set of bookshelves. Input Line 1: Two space-separated integers: N and L. Lines 2..1+N: Line i+1 contains two space-separated integers: H(i) and W(i). (1 <= H(i) <= 1,000,000; 1 <= W(i) <= L). Output  Line 1: The minimum possible total height for the set of bookshelves. Sample Input Copy sample input to clipboard 5 10 5 7 9 2 8 5 13 2 3 8 Sample Output 21 Hint  There are 3 shelves, the first containing just book 1 (height 5, width 7), the second containing books 2..4 (height 13, width 9), and the third containing book 5 (height 3, width 8). Problem Source: 2013年每周一赛第⑨场 #include <cstdio> #include <iostream> #include <vector> #include <set> #include <cstring> #include <string> #include <map> #include <cmath> #include <ctime> #include <algorithm> #include <queue> using namespace std; #define INF 0x7fffffff #define maxm 1001 #define mp make_pair #define pb push_back #define rep(i,n) for(int i = 0; i < (n); i++) #define re return #define fi first #define se second #define sz(x) ((int) (x).size()) #define all(x) (x).begin(), (x).end() #define sqr(x) ((x) * (x)) #define sqrt(x) sqrt(abs(x)) #define y0 y3487465 #define y1 y8687969 #define fill(x,y) memset(x,y,sizeof(x)) typedef vector<int> vi; typedef long long ll; typedef long double ld; typedef double D; typedef pair<int, int> ii; typedef vector<ii> vii; typedef vector<string> vs; typedef vector<vi> vvi; template<class T> T abs(T x) { re x > 0 ? x : -x; } const int maxn = 2005; int n, m; int h[maxn], w[maxn]; int dp[maxn]; int main(){ while (~scanf("%d%d", &n, &m)){ for (int i = 0; i <= n; i++)dp[i] = INF; dp[0] = 0; for (int i = 1; i <= n; i++){ scanf("%d%d", &h[i], &w[i]); int sum = 0, x = 0; for (int j = i; j >= 0; j--){ if (sum + w[j] <= m)sum += w[j]; else break; x = max(x, h[j]); dp[i] = min(dp[i], dp[j - 1] + x); } } printf("%d\n", dp[n]); } return 0; }