ST表模板题,套板子即可
ST表模板:点我打开链接
代码:
#include<cstdio> #include<cmath> #include<cstring> #include<string> #include<cstdlib> #include<algorithm> #include<iostream> #include<queue> #include<stack> #include<map> using namespace std; #define FOU(i,x,y) for(int i=x;i<=y;i++) #define FOD(i,x,y) for(int i=x;i>=y;i--) #define MEM(a,val) memset(a,val,sizeof(a)) #define PI acos(-1.0) const double EXP = 1e-9; typedef long long ll; typedef unsigned long long ull; const int INF = 0x3f3f3f3f; const ll MINF = 0x3f3f3f3f3f3f3f3f; const double DINF = 0xffffffffffff; const int mod = 1e9+7; const int N = 1e5+5; int dpMin[N][20],dpMax[N][20]; int a[N]; int n,q; void Init() { for(int i=1;i<=n;i++) dpMin[i][0] = dpMax[i][0] = a[i]; for (int j=1;j<=log(n)/log(2);j++) //只能j在外,i在内 { for(int i=1;i<=n;i++) { if (i+(1<<j)-1<=n) { dpMin[i][j]=min(dpMin[i][j-1],dpMin[i+(1<<(j-1))][j-1]); dpMax[i][j]=max(dpMax[i][j-1],dpMax[i+(1<<(j-1))][j-1]); } else break; } } } int ST_min(int l,int r) { int k=log(r-l+1)/log(2.0); return min(dpMin[l][k],dpMin[r-(1<<k)+1][k]); } int ST_max(int l,int r) { int k=log(r-l+1)/log(2.0); return max(dpMax[l][k],dpMax[r-(1<<k)+1][k]); } int main() { //freopen("in.txt","r",stdin); //freopen("out.txt","w",stdout); std::ios::sync_with_stdio(false); int l,r; while(~scanf("%d%d",&n,&q)) { for(int i=1;i<=n;i++) scanf("%d",&a[i]); Init(); while(q--) { scanf("%d%d",&l,&r); printf("%d\n",ST_max(l,r)); } } return 0; }