codeforces 1217E E. Sum Queries? (线段树

codeforces 1217E E. Sum Queries? (线段树

传送门:https://codeforces.com/contest/1217/problem/E

题意:

n个数,m次询问

单点修改

询问区间内最小的unbalanced number

balanced number定义是,区间内选取数字的和sum

sum上的每一位都对应着选取的数上的一位

否则就是unbalanced number

题解:

根据题意

如果区间存在unbalance number,那么一定存在两个数就可以组成unbalance number

为什么?

因为根据balanced number的定义来说,只要在和的一位上 有两个数字在这个位置上的数都不为0的话那么这两个数字一定可以组成unbalanced number,所以我们需要对每一位非0的数进行操作

值域最多为2e9,所以我们建立十颗线段树,保存每一位上的 如果当前位不为0,保存这个位置上所在数的最小值

记录一个保存答案的线段树,答案就为 当前位的两个数都不为0的两数之和的最小值

代码:

/**
 *        ┏┓    ┏┓
 *        ┏┛┗━━━━━━━┛┗━━━┓
 *        ┃       ┃  
 *        ┃   ━    ┃
 *        ┃ >   < ┃
 *        ┃       ┃
 *        ┃... ⌒ ...  ┃
 *        ┃       ┃
 *        ┗━┓   ┏━┛
 *          ┃   ┃ Code is far away from bug with the animal protecting          
 *          ┃   ┃   神兽保佑,代码无bug
 *          ┃   ┃           
 *          ┃   ┃        
 *          ┃   ┃
 *          ┃   ┃           
 *          ┃   ┗━━━┓
 *          ┃       ┣┓
 *          ┃       ┏┛
 *          ┗┓┓┏━┳┓┏┛
 *           ┃┫┫ ┃┫┫
 *           ┗┻┛ ┗┻┛
 */
// warm heart, wagging tail,and a smile just for you!
//
//                            _ooOoo_
//                           o8888888o
//                           88" . "88
//                           (| -_- |)
//                           O\  =  /O
//                        ____/`---'\____
//                      .'  \|     |//  `.
//                     /  \|||  :  |||//  \
//                    /  _||||| -:- |||||-  \
//                    |   | \  -  /// |   |
//                    | \_|  ''\---/''  |   |
//                    \  .-\__  `-`  ___/-. /
//                  ___`. .'  /--.--\  `. . __
//               ."" '<  `.___\_<|>_/___.'  >'"".
//              | | :  `- \`.;`\ _ /`;.`/ - ` : | |
//              \  \ `-.   \_ __\ /__ _/   .-` /  /
//         ======`-.____`-.___\_____/___.-`____.-'======
//                            `=---='
//        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
//                     佛祖保佑      永无BUG
#include <set>
#include <map>
#include <stack>
#include <cmath>
#include <queue>
#include <cstdio>
#include <string>
#include <vector>
#include <cstring>
#include <iostream>
#include <algorithm>
using namespace std;
typedef long long LL;
typedef pair<int, int> pii;
typedef unsigned long long uLL;
#define ls rt<<1
#define rs rt<<1|1
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
#define bug printf("*********\n")
#define FIN freopen("input.txt","r",stdin);
#define FON freopen("output.txt","w+",stdout);
#define IO ios::sync_with_stdio(false),cin.tie(0)
#define debug1(x) cout<<"["<<#x<<" "<<(x)<<"]\n"
#define debug2(x,y) cout<<"["<<#x<<" "<<(x)<<" "<<#y<<" "<<(y)<<"]\n"
#define debug3(x,y,z) cout<<"["<<#x<<" "<<(x)<<" "<<#y<<" "<<(y)<<" "<<#z<<" "<<z<<"]\n"
const int maxn = 3e5 + 5;
const int INF = 2e9+7;
const int mod = 1e9 + 7;
const double Pi = acos(-1);
LL gcd(LL a, LL b) {
    return b ? gcd(b, a % b) : a;
}
LL lcm(LL a, LL b) {
    return a / gcd(a, b) * b;
}
double dpow(double a, LL b) {
    double ans = 1.0;
    while(b) {
        if(b % 2)ans = ans * a;
        a = a * a;
        b /= 2;
    } return ans;
}
LL quick_pow(LL x, LL y) {
    LL ans = 1;
    while(y) {
        if(y & 1) {
            ans = ans * x % mod;
        } x = x * x % mod;
        y >>= 1;
    } return ans;
}
LL a[maxn];
LL Min[maxn << 2][15];
LL ANS[maxn << 2];
void push_up(int rt) {
    ANS[rt] = INF;
    for(int i = 0; i <= 12; i++) {
        if(Min[ls][i] != INF && Min[rs][i] != INF) {
            ANS[rt] = min(ANS[rt], Min[ls][i] + Min[rs][i]);
        }
        Min[rt][i] = min(Min[ls][i], Min[rs][i]);
    }
    ANS[rt] = min(ANS[rt], min(ANS[ls], ANS[rs]));
}
void build(int l, int r, int rt) {
    ANS[rt] = INF;
    if(l == r) {
        int tmp = a[l];
        // debug1(tmp);
        for(int i = 0; i <= 12; i++) {
            int val = tmp % 10;
            if(val == 0) Min[rt][i] = INF;
            else Min[rt][i] = a[l];
            tmp /= 10;
        }
        return;
    }
    int mid = (l + r) >> 1;
    build(lson);
    build(rson);
    push_up(rt);
}
void update(int pos, int x, int l, int r, int rt) {
    if(l == r) {
        int tmp = x;
        ANS[rt] = INF;
        // debug1(tmp);
        for(int i = 0; i <= 12; i++) {
            int val = tmp % 10;
            if(val == 0)   Min[rt][i] = INF;
            else Min[rt][i] = x;
            // Min[rt][i] = val;
            // debug2(val,Min[rt][i]);
            tmp /= 10;
        }
        return;
    }
    int mid = (l + r) >> 1;
    if(pos <= mid) update(pos, x, lson);
    else update(pos, x, rson);
    push_up(rt);
}
LL res[15];
LL ans = INF;
void query(int L, int R, LL &ans, int l, int r, int rt) {
    // if(l > R || r < L)  return;
    if(L <= l && r <= R) {
        for(int i = 0; i <= 12; i++) {
            if(res[i] != INF && Min[rt][i] != INF) {
                ans = min(ans, res[i] + Min[rt][i]);
            }
        }
        for(int i = 0; i <= 10; i++) {
            res[i] = min(res[i], Min[rt][i]);
        }
        ans = min(ANS[rt], ans);
        return;
    }
    int mid = (l + r) >> 1;
    if(L <= mid) query(L, R, ans, lson);
    if(R > mid)  query(L, R, ans, rson);
}
int main() {
#ifndef ONLINE_JUDGE
    FIN
#endif
    int n, m;
    scanf("%d%d", &n, &m);
    for(int i = 1; i <= n; i++) {
        scanf("%d", &a[i]);
    }
    build(1, n, 1);
    while(m--) {
        int op, l, r, pos, x;
        scanf("%d", &op);
        if(op == 1) {
            scanf("%d%d", &pos, &x);
            update(pos, x, 1, n, 1);
        } else {
            scanf("%d%d", &l, &r);
            ans = INF;
            for(int i = 0; i <= 12; i++) res[i] = INF;
            query(l, r, ans, 1, n, 1);
            if(ans == INF) ans = -1;
            printf("%lld\n", ans);
        }
    }
    return 0;
}
posted @ 2019-09-10 10:33  buerdepepeqi  阅读(597)  评论(0编辑  收藏  举报