csu 1110 RMQ with Shifts （线段树单点更新）

#include <cstdio>
#include <cstring>
#include <queue>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <cstdlib>
#define lson l,m,rt<<1
#define rson m + 1,r ,rt<<1|1
using namespace std;
const int maxn = 120005;
int node[maxn<<2];
int n,m,a[maxn],shift[maxn];
void up(int rt)
{
    node[rt] = min(node[rt<<1],node[rt<<1|1]);
}
void build(int l,int r,int rt)
{
    if(l == r)
    {
        scanf("%d",&node[rt]);
        a[l] = node[rt];
        return;
    }
    int m = (l + r) >> 1;
    build(lson);
    build(rson);
    up(rt);
}
int A,B;
void update(int l,int r,int rt)
{
    if(l == r)
    {
        node[rt] = B;
        return;
    }
    int m = (l + r) >> 1;
    if(A <= m) update(lson);
    else update(rson);
    up(rt);
}
int ans;
void qurry(int l,int r,int rt)
{
    if(A <= l && r <= B)
    {
        ans = min(ans,node[rt]);
        return;
    }
    int m = (l + r) >> 1;
    if(A <= m) qurry(lson);
    if(B > m) qurry(rson);
}
int main()
{
    while(scanf("%d %d",&n,&m) != EOF)
    {
        build(1,n,1);
        char str[105];
        while(m--)
        {
            scanf("%s",str);
            int i = 6,len = 0;
            if(str[0] == ‘q‘)
            {
                /*
                shift[0] = 0;
                for(; str[i] != ‘)‘; i++)
                {
                    if(str[i] == ‘,‘)
                    {
                        len++;
                        shift[len] = 0;
                        continue;
                    }
                    shift[len] = shift[len] * 10 + str[i] - 48;
                }
                len++;
                A = shift[0],B = shift[1];*/
                 
                sscanf(str+5,"(%d,%d)",&A,&B);
                 
                ans = maxn * 100;
                qurry(1,n,1);
                printf("%d\n",ans);
            }
            else
            {
                shift[0] = 0;
                for(; str[i] != ‘)‘; i++)
                {
                    if(str[i] == ‘,‘)
                    {
                        len++;
                        shift[len] = 0;
                        continue;
                    }
                    shift[len] = shift[len] * 10 + str[i] - 48;
                }
                len++;
                //printf("len  = %d\n",len);
                for(i = 0; i < len - 1; i++)
                {
                    A = shift[i],B = a[shift[i+1]];
                   // printf("A = %d B = %d\n",A,B);
                    update(1,n,1);
                }
                A = shift[i],B = a[shift[0]];
                //printf("A = %d B = %d\n",A,B);
                update(1,n,1);
                int tmp = a[shift[0]];
                for(i = 0; i < len - 1; i++)
                {
                    a[shift[i]] = a[shift[i+1]];
                }
                a[shift[i]] = tmp;
            }
        }
    }
    return 0;
}