LOJ#6284. 数列分块入门 8
分块的时候开一个数组标记这个区间是不是都是一样颜色的部分,如果是的话,我后面的查询,更新部分就可以直接整块操作,对于不是不全部都一样颜色的块在具体进到快里面去暴力。
在更新的时候对边上的两个不完整的块,先暴力把这个地方的标记下推下去,然后我在给它重新标记
#include<map> #include<set> #include<ctime> #include<cmath> #include<stack> #include<queue> #include<string> #include<vector> #include<cstdio> #include<cstdlib> #include<cstring> #include<iostream> #include<algorithm> #define first fi #define second se #define lowbit(x) (x & (-x)) typedef unsigned long long int ull; typedef long long int ll; const double pi = 4.0*atan(1.0); const int inf = 0x3f3f3f3f; const int maxn = 100005; const int maxm = 100000; const int mod = 10007; using namespace std; int n, m, tol, T; int block; int a[maxn]; int add[maxn]; bool vis[maxn]; int belong[maxn]; void init() { memset(a, 0, sizeof a); memset(add, 0, sizeof add); memset(vis, false, sizeof vis); memset(belong, 0, sizeof belong); } int L(int x) { return (x-1)*block + 1; } int R(int x) { return min(n, x*block); } void update(int l, int r, int c) { if(vis[belong[l]]) { for(int i=L(belong[l]); i<=R(belong[l]); i++) a[i] = add[belong[i]]; vis[belong[l]] = false; } for(int i=l; i<=min(r, R(belong[l])); i++) a[i] = c; if(belong[l] == belong[r]) return ; if(belong[l] != belong[r]) { if(vis[belong[r]]) { for(int i=L(belong[r]); i<=R(belong[r]); i++) a[i] = add[belong[i]]; vis[belong[r]] = false; } for(int i=L(belong[r]); i<=r; i++) a[i] = c; } for(int i=belong[l]+1; i<belong[r]; i++) { add[i] = c; vis[i] = true; } } int query(int l, int r, int c) { int ans = 0; if(vis[belong[l]]) { if(add[belong[l]] == c) ans += min(R(belong[l]), r) - l + 1; } else { for(int i=l; i<=min(R(belong[l]), r); i++) ans += (a[i]==c); } if(belong[l] == belong[r]) return ans; if(belong[l] != belong[r]) { if(vis[belong[r]]) { if(add[belong[r]] == c) ans += r - L(belong[r]) + 1; } else { for(int i=L(belong[r]); i<=r; i++) ans += (a[i] == c); } } for(int i=belong[l]+1; i<belong[r]; i++) { if(vis[i]) { if(add[i] == c) ans += R(i) - L(i) + 1; } else { for(int j=L(i); j<=R(i); j++) { ans += (a[j] == c); } } } return ans; } int main() { while(~scanf("%d", &n)) { init(); block = sqrt(n); for(int i=1; i<=n; i++) { scanf("%d", &a[i]); belong[i] = (i-1) / block + 1; } m = n; while(m--) { int l, r, c; scanf("%d%d%d", &l, &r, &c); int ans = query(l, r, c); update(l, r, c); printf("%d\n", ans); } } return 0; }