UVa 1149 Bin Packing (二分 + 贪心)

来源：互联网发布：苹果清除缓存软件编辑：程序博客网时间：2024/06/13 21:59

UVA 第一次用不会用, 输出错误竟然发邮箱 , 好贴心的操作

贪心, 按照从小到大排序, 然后二分背包数目, 因为背包最大就是 n

所以

#include <iostream>#include <stdio.h>#include <algorithm>#include <cmath>#include <math.h>#include <cstring>#include <string>#include <queue>#include <stack>#include <stdlib.h>#include <list>#include <map>#include <set>#include <bitset>#include <vector>#define mem(a,b) memset(a,b,sizeof(a))#define findx(x) lower_bound(b+1,b+1+bn,x)-b#define FIN      freopen("input.txt","r",stdin)#define FOUT     freopen("output.txt","w",stdout)#define S1(n)    scanf("%d",&n)#define SL1(n)   scanf("%I64d",&n)#define S2(n,m)  scanf("%d%d",&n,&m)#define SL2(n,m)  scanf("%I64d%I64d",&n,&m)#define Pr(n)     printf("%d\n",n)using namespace std;typedef long long ll;const double PI=acos(-1);const int INF=0x3f3f3f3f;const double esp=1e-6;const int maxn=1e6+5;const int MOD=1e9+7;const int mod=1e9+7;int dir[5][2]={0,1,0,-1,1,0,-1,0};int a[maxn];int b[maxn];int n;int L;int judge(int x){    int k=1;    mem(b,0);    for(int i=n;i>=n-x+1;i--)        b[k++]=a[i];    k--;    for(int i=n-x;i>=1;i--)    {        if(a[i]+b[k--]>L)            return 1;    }    return 0;}int main(){    int t;    cin>>t;    while(t--)    {        cin>>n;        mem(a,0);        cin>>L;        for(int i=1;i<=n;i++)        {            S1(a[i]);        }        sort(a+1,a+n+1);        int l=1,r=n;        while(r-l>1)        {            int mid=(l+r)>>1;            if(judge(mid))                l=mid;            else                r=mid;        }        printf("%d\n",r);        if(t>0)            printf("\n");    }    return 0;}

123

阅读全文

0 0