个人模板 ST表

xiaoxiao2021-02-28  96

#include <bits/stdc++.h> using namespace std; const int N = 1e5 + 10; int a[N]; int f[N][16]; int n; void rmq_init() //建立:dp(i,j) = min{dp(i,j-1),dp(i+2^(j-1),j-1) O(nlogn) { for (int i = 1; i <= n; i++) f[i][0] = a[i]; int k = floor(log((double)n) / log(2.0)); //C/C++取整函数ceil()大,floor()小 for (int j = 1; j <= k; j++) for (int i = 1; i <= n; i++) { if (i + (1 << (j - 1)) <= n) //f(i,j) = min{f(i,j-1),f(i+2^(j-1),j-1) f[i][j] = max(f[i][j - 1], f[i + (1 << (j - 1))][j - 1]); ///改为 min 可求最小值 } } int rmq(int i, int j) //查询:返回区间[i,j]的最小值 { int k = floor(log((double)(j - i + 1)) / log(2.0)); return max(f[i][k], f[j - (1 << k) + 1][k]); ///改为 min 可求最小值 } int main() { int icase = 0; while(scanf("%d", &n)!=EOF) { memset(a,0,sizeof(a)); memset(f,0,sizeof(f)); for (int i = 1; i <= n; i++) scanf("%d", &a[i]); rmq_init(); int m; printf("Case %d:\n",++icase); scanf("%d",&m); for(int i = 0; i < m; i++) { int x,y; scanf("%d%d",&x,&y); printf("%d\n",rmq(x,y)); } } }
转载请注明原文地址: https://www.6miu.com/read-43903.html

最新回复(0)