首页 > 代码库 > CF#52 C Circular RMQ （线段树区间更新）

CF#52 C Circular RMQ （线段树区间更新）

2024-07-17 16:38:42   221人阅读

Description

You are given circular array a0,?a1,?...,?an?-?1. There are two types of operations with it:

  • inc(lf,?rg,?v) — this operation increases each element on the segment[lf,?rg] (inclusively) by v;
  • rmq(lf,?rg) — this operation returns minimal value on the segment[lf,?rg] (inclusively).

Assume segments to be circular, so if n?=?5 andlf?=?3,?rg?=?1, it means the index sequence:3,?4,?0,?1.

Write program to process given sequence of operations.

Input

The first line contains integer n (1?≤?n?≤?200000). The next line contains initial state of the array:a0,?a1,?...,?an?-?1 (?-?106?≤?ai?≤?106),ai are integer. The third line contains integerm (0?≤?m?≤?200000),m — the number of operartons. Next m lines contain one operation each. If line contains two integer lf,?rg (0?≤?lf,?rg?≤?n?-?1) it meansrmq operation, it contains three integers lf,?rg,?v (0?≤?lf,?rg?≤?n?-?1;?-?106?≤?v?≤?106) — inc operation.

Output

For each rmq operation write result for it. Please, do not use%lld specificator to read or write 64-bit integers in C++. It is preffered to usecout (also you may use %I64d).

Sample Input

Input 
41 2 3 443 03 0 -10 12 1
Output 
100

题意很好理解。

如果a>b的话，就查0~b和a~n-1，其余的就是线段树区间更新模板，判断m个询问里是否存在c，详见代码，很好理解。


#include <stdio.h>
#include <string.h>
#include <algorithm>
#include <math.h>
#include <ctype.h>
#include <iostream>
#define lson o << 1, l, m
#define rson o << 1|1, m+1, r
using namespace std;
typedef __int64 LL;
const __int64 MAX =  9223372036854775807;
const int maxn = 200010;
int n, a, q, c, b;
char str[1200];
LL mi[maxn<<2], add[maxn<<2];
void up(int o) {
    mi[o] = min(mi[o<<1], mi[o<<1|1]);
}
void down(int o) {
    if(add[o]) {
        add[o<<1] += add[o];
        add[o<<1|1] += add[o];
        mi[o<<1] += add[o];
        mi[o<<1|1] += add[o];
        add[o] = 0;
    }
}
void build(int o, int l, int r) {
    if(l == r) {
        scanf("%I64d", &mi[o]);
        return;
    }
    int m = (l+r) >> 1;
    build(lson);
    build(rson);
    up(o);
}
void update(int o, int l, int r) {
    if(a <= l && r <= b) {
        add[o] += c;
        mi[o] += c;
        return ;
    }
    down(o);
    int m = (l+r) >> 1;
    if(a <= m) update(lson);
    if(m < b ) update(rson);
    up(o);
}
LL query(int o, int l, int r) {
    if(a <= l && r <= b) return mi[o];
    down(o);
    int m = (l+r) >> 1;
    LL res = MAX;
    if(a <= m) res = query(lson);
    if(m < b ) res = min(res, query(rson));
    return res;
}
int main()
{
    scanf("%d", &n);
    build(1, 0, n-1);
    scanf("%d", &q); getchar(); while(q--) {
        gets(str);
        if(sscanf(str,"%d %d %d", &a, &b, &c) == 3)  {
            if(a <= b) update(1, 0, n-1);
            else {
                int tmp = b;
                b = n-1; update(1, 0, n-1);
                a = 0, b = tmp; update(1, 0, n-1);
            }
        } else {
            LL ans ;
            if(a <= b) ans = query(1, 0, n-1);
            else {
                int tmp = b;
                b = n-1; ans = query(1, 0, n-1);
                a = 0, b = tmp; ans = min(ans, query(1, 0, n-1));
            }
            printf("%I64d\n", ans);
        }
    }
    return 0;
}





联系
我们