- 题目
At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of important things were lost, in particular the favorite sequence of Picks.
Fortunately, Picks remembers how to repair the sequence. Initially he should create an integer array a[1], a[2], ..., a[n]. Then he should perform a sequence of m operations. An operation can be one of the following:
- Print operation l, r. Picks should write down the value of .
- Modulo operation l, r, x. Picks should perform assignment a[i] = a[i] mod x for each i (l ≤ i ≤ r).
- Set operation k, x. Picks should set the value of a[k] to x (in other words perform an assignment a[k] = x).
Can you help Picks to perform the whole sequence of operations?
InputThe first line of input contains two integer: n, m (1 ≤ n, m ≤ 105). The second line contains n integers, separated by space: a[1], a[2], ..., a[n] (1 ≤ a[i] ≤ 109) — initial value of array elements.
Each of the next m lines begins with a number type .
- If type = 1, there will be two integers more in the line: l, r (1 ≤ l ≤ r ≤ n), which correspond the operation 1.
- If type = 2, there will be three integers more in the line: l, r, x (1 ≤ l ≤ r ≤ n; 1 ≤ x ≤ 109), which correspond the operation 2.
- If type = 3, there will be two integers more in the line: k, x (1 ≤ k ≤ n; 1 ≤ x ≤ 109), which correspond the operation 3.
For each operation 1, please print a line containing the answer. Notice that the answer may exceed the 32-bit integer.
Sample 1Input Output 5 5 1 2 3 4 5 2 3 5 4 3 3 5 1 2 5 2 1 3 3 1 1 3
8 5
Inputcopy Outputcopy 10 10 6 9 6 7 6 1 10 10 9 5 1 3 9 2 7 10 9 2 5 10 8 1 4 7 3 3 7 2 7 9 9 1 2 4 1 6 6 1 5 9 3 1 10
49 15 23 1 9
Consider the first testcase:
- At first, a = {1, 2, 3, 4, 5}.
- After operation 1, a = {1, 2, 3, 0, 1}.
- After operation 2, a = {1, 2, 5, 0, 1}.
- At operation 3, 2 + 5 + 0 + 1 = 8.
- After operation 4, a = {1, 2, 2, 0, 1}.
- At operation 5, 1 + 2 + 2 = 5.
- 思路
线段树,操作有区间求和,区间取模,单点修改
每次全部取模的话必定超时,所以要剪枝,因为每次取模之后数组里的数要么不变要么变小,除非修改之后才有可能变大,可以存储每个节点代表的数组区间中元素的最大值,如果最大的数都比模数小,很明显这个区间就没必要继续模了,直接跳过。数据强度似乎不大,这么剪就能直接过了。 - 代码
#include<cstdio> #include<iostream> #include<string> #include<cstring> #include<algorithm> using namespace std; #define ll long long ll d[1000000],a[1000005],maxx[1000005];//区间值,原始值 ll n,q,mod; void build(ll s, ll t, ll p) { if (s == t) { maxx[p] = d[p] = a[s]; return; } ll m = s + ((t - s) >> 1); build(s, m, p * 2), build(m + 1, t, p * 2 + 1); d[p] = d[p * 2] + d[(p * 2) + 1]; maxx[p]=max(maxx[p * 2],maxx[(p * 2) + 1]); } void update(ll l, ll c, ll s, ll t, ll p) { if (l == s && t == l) { d[p] = c; maxx[p] = c; return; } ll m = s + ((t - s) >> 1); if (l <= m) update(l, c, s, m, p * 2); else update(l, c, m + 1, t, p * 2 + 1); d[p] = d[p * 2] + d[p * 2 + 1]; maxx[p]=max(maxx[p * 2],maxx[(p * 2) + 1]); } void updatemo(int l,int r,int mod,int s,int t,int p) { if(maxx[p] < mod) return; if(s == t) { d[p] %= mod; maxx[p] = d[p]; return; } int m = s + ((t - s) >> 1); if (l <= m) updatemo(l, r, mod, s, m, p * 2); if (r > m) updatemo(l, r, mod, m + 1, t, p * 2 + 1); d[p] = d[p * 2] + d[(p * 2) + 1]; maxx[p]=max(maxx[p * 2],maxx[(p * 2) + 1]); } ll getsum(ll l, ll r, ll s, ll t, ll p) { if (l <= s && t <= r) return d[p]; ll m = s + ((t - s) >> 1); ll sum = 0; if (l <= m) sum += getsum(l, r, s, m, p * 2); if (r > m) sum += getsum(l, r, m + 1, t, p * 2 + 1); return sum; } int main() { scanf("%lld%lld",&n,&q); for(int i=1;i<=n;i++){ scanf("%lld",&a[i]); } build(1,n,1); ll op,x,y,mod; while (q--) { cin >> op; if (op == 1) cin >> x >> y,cout << getsum(x, y, 1, n, 1) <<endl; else if(op == 2) cin >> x >> y >> mod, updatemo(x, y, mod, 1, n, 1); else cin >> x >> y,update(x, y, 1, n, 1); } }