RMQ和LCA
阿新 • • 發佈:2018-11-10
RMQ
void ST(int n) { for (int i = 1; i <= n; i++) dp[i][0] = a[i]; for (int j = 1; (1 << j) <= n; j++) {//2^j for (int i = 1; i + (1 << j) - 1 <= n; i++) { dp[i][j] = max(dp[i][j - 1], dp[i + (1 << (j - 1))][j - 1]); } } } int RMQ(int l, int r) { if(l>r) return 0; int k = 0; while ((1 << (k + 1)) <= r - l + 1) k++; return max(dp[l][k], dp[r - (1 << k) + 1][k]); }
void ST() { int i,j,k; for(i=1;i<=n;i++) MAX[i][0]=f[i]; k=log((double)(n+1))/log(2.0); for(j=1;j<=k;j++) for(i=1;i+(1<<j)-1<=n;i++) MAX[i][j]=max(MAX[i][j-1],MAX[i+(1<<(j-1))][j-1]); } int rmq_max(int l,int r) { if(l>r) return 0; int k=log((double)(r-l+1))/log(2.0); return max(MAX[l][k],MAX[r-(1<<k)+1][k]); }