一维和二维ST模板

void init(){
    for (int i = 0; i < n; i++) st[i][0] = a[i];
    for (int j = 1; (1 << j) <= n; j++){
        for (int i = 0; i + (1 << j) - 1 < n; i++){
            st[i][j] = min(st[i + (1 << (j-1))][j - 1], st[i][j - 1]);
        }
    }
}

inline int query(int l, int r){
    int len = r - l + 1;
    int k = 0;
    while ((1 << (k + 1)) <= len) k++;
    return min(st[l][k], st[r - (1 << k) + 1][k]);
}

 

 

二维：

定义dp(i, j, k, L)表示以(i,j)为左上角，宽度为(2^k, 2^L)的区间内的某个数值

int dp[maxn][maxn][8][8], dp2[maxn][maxn][8][8];

void init_st(){
    for (int i = 0; (1 << i) <= n; i++){
        for (int j = 0; (1 << j) <= n; j++){
            if (i == 0 && j == 0) continue;
            for (int x = 1; x + (1 << i) - 1 <= n; x++){
                for (int y = 1; y + (1 << j) - 1 <= n; y++){
                    if (i == 0) {
                        dp[x][y][i][j] = min(dp[x][y][i][j - 1], dp[x][y + (1 << (j - 1))][i][j - 1]);
                        dp2[x][y][i][j] = max(dp2[x][y][i][j - 1], dp2[x][y + (1 << (j - 1))][i][j - 1]);
                    }
                    else {
                        dp[x][y][i][j] = min(dp[x][y][i - 1][j], dp[x + (1 << (i - 1))][y][i - 1][j]);
                        dp2[x][y][i][j] = max(dp2[x][y][i - 1][j], dp2[x + (1 << (i - 1))][y][i - 1][j]);
                    }
                }
            }
        }
    }
}

int query(int x, int y, int X, int Y){
    int maxi = 0, mini = 1e8;
    int k1 = 0, k2 = 0;
    while (1 << (1 + k1) <= X - x) k1++;
    while (1 << (1 + k2) <= Y - y) k2++;
    maxi = max(maxi, max(dp2[x][y][k1][k2], dp2[X - (1 << k1) + 1][y][k1][k2]));
    maxi = max(maxi, max(dp2[x][Y - (1 << k2) + 1][k1][k2], dp2[X - (1 << k1) + 1][Y - (1 << k2) + 1][k1][k2]));

    mini = min(mini, min(dp[x][y][k1][k2], dp[X - (1 << k1) + 1][y][k1][k2]));
    mini = min(mini, min(dp[x][Y - (1 << k2) + 1][k1][k2], dp[X - (1 << k1) + 1][Y - (1 << k2) + 1][k1][k2]));
    //printf("maxi = %d mini = %d\n", maxi, mini);
    return maxi - mini;
}