Time Limit: 1000MS | Memory Limit: 65536K | |
Total Submissions: 31350 | Accepted: 13943 |
Description
Bessie has gone to the mall's jewelry store and spies a charm bracelet. Of course, she'd like to fill it with the best charms possible from theN (1 ≤ N ≤ 3,402) available charms. Each charm i in the supplied list has a weightWi (1 ≤ Wi ≤ 400), a 'desirability' factorDi (1 ≤ Di ≤ 100), and can be used at most once. Bessie can only support a charm bracelet whose weight is no more thanM (1 ≤ M ≤ 12,880).
Given that weight limit as a constraint and a list of the charms with their weights and desirability rating, deduce the maximum possible sum of ratings.
Input
* Line 1: Two space-separated integers: N and M
* Lines 2..N+1: Line i+1 describes charm i with two space-separated integers:Wi and Di
Output
* Line 1: A single integer that is the greatest sum of charm desirabilities that can be achieved given the weight constraints
Sample Input
4 6 1 4 2 6 3 12 2 7
Sample Output
23
Source
简单O1背包水题,温习一下,瞬秒。
此题智能用一维DP数组,二维妥妥超内存。
一维AC
#include <stdio.h> #include <algorithm> #include <string.h> using namespace std; const int MAXN=3405; const int MAXM=12885; int dp[MAXM]; int weight[MAXN]; int value[MAXN]; int main() { int n,m; while(scanf("%d%d",&n,&m)>0) { memset(dp,0,sizeof(dp)); for(int i=1;i<=n;i++) scanf("%d%d",&weight[i],&value[i]); for(int i=1;i<=n;i++) for(int j=m;j>=weight[i];j--) dp[j]=max(dp[j-weight[i]]+value[i],dp[j]); printf("%d\n",dp[m]); } return 0; }
二维数组,方法正确,但此题会超内存
#include <stdio.h> #include <algorithm> #include <string.h> using namespace std; const int MAXN=3405; const int MAXM=12885; int dp[MAXN][MAXM]; int weight[MAXN]; int value[MAXN]; int main() { int n,m; while(scanf("%d%d",&n,&m)>0) { memset(dp,0,sizeof(dp)); for(int i=1;i<=n;i++) scanf("%d%d",&weight[i],&value[i]); for(int i=1;i<=n;i++) for(int j=1;j<=m;j++) { dp[i][j]=dp[i-1][j]; if(j>=weight[i]) dp[i][j]=max(dp[i-1][j],dp[i-1][j-weight[i]]+value[i]); } printf("%d\n",dp[n][m]); } return 0; }