12124 Assemble【二分】

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利用二分枚举所有 品质

思路想出来比较好写代码：

#include<cstdio>
#include<map>
#include<string>
#include<vector>
#include<set>
#include<cstring>
#include<algorithm>
using namespace std;
const int maxn = 1111;
//种类  名称  价格  价格因子
int n,b;
int cnt;
int min_v,max_v;
struct Th{
    int price;
    int level;
    Th(int x,int y){
        price = x;  level = y;
    }
};
map<string,int>List;
vector<Th>arr[maxn];
void debug(){
    printf("[%d]\n",cnt);
    for(int i = 0; i < cnt; i++){
        printf("-> %d\n",i);
        for(int j = 0; j < arr[i].size(); j++)
            printf("%d %d\n",arr[i][j].price,arr[i][j].level);
    }
}
void solve(){
    //printf("%d %d\n",min_v,max_v);
    int l = min_v, r = max_v;
    while(l < r){
        int mid = l + (r - l + 1) / 2;
        int ok  = 1;
        int price_ans = 0;
        for(int i = 0; i < cnt; i++){
            int price = -1;
            for(int j = 0; j < arr[i].size(); j++){
                if(arr[i][j].level >= mid){
                    if(price == -1)
                        price = arr[i][j].price;
                    else
                        price = min(price,arr[i][j].price);
                }
            }
            if(price < 0){ok = 0; break;}
            else
                price_ans += price;
        }
        if(price_ans > b) ok = 0;
        if(ok){         // [mid ~ r]
            l = mid;
        }
        else            // [l ~ mid)
            r = mid - 1;
    }
    printf("%d\n",l);
}
int main(){
    int T;
    scanf("%d",&T);
    while(T--){
        scanf("%d%d",&n,&b);

        List.clear();
        cnt = 0;

        min_v = 1100000000;
        max_v = -1;

        for(int i = 0; i < n; i++){
            char kind[50];
            int price,level;
            scanf("%s%*s%d%d",kind,&price,&level);

            min_v = min(min_v,level);
            max_v = max(max_v,level);

            string ki(kind);
            if(!List.count(ki)){
                List[ki] = cnt ++;
            }
            arr[List[ki]].push_back(Th(price,level));
        }
        //debug();
        solve();
        for(int i = 0; i < cnt; i++) arr[i].clear();
    }
    return 0;
}

12124 Assemble【二分】

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原文地址：http://blog.csdn.net/u013451221/article/details/44276401