for (int h = 0; h < 4; h++) {
int minValue = a[h][0];
for (int i = h; i < h + 1; i++) {
for (j = w; j < w + 3; j++) {
if (a[i][j] < minValue) {
minValue = a[i][j];
}
}
}
System.out.println("Minimum Value = " + minValue);
}
我想找到接缝雕刻，但算法效果不佳。据我所知，我需要在所选索引下找到最小值
我不确定您的代码会找到最小的接缝：有一种“简单”的动态编程方法可以做到这一点：
private static int[][] findHorizontalSeam(double[][] energyTable) {
int[][] seam;
int width = energyTable.length;
int height = energyTable[0].length;
// seamDynamic is the table we will use for dynamic programming.
double[][] seamDynamic = new double[width][height];
int[][] backtracker = new int[width][height];
double minimum;
// horizontal seam.
seam = new int[energyTable.length][2];
// Loops over the energy table and finds the lowest energy path.
for (int x = 0; x < width; x++) {
for (int y = 0; y < height; y++) {
if (x == 0) {
seamDynamic[x][y] = energyTable[x][y];
backtracker[x][y] = -1;
} else {
// every other column.
// need to special case the top/bottom.
if (y == 0) {
minimum = Math.min(seamDynamic[x - 1][y], seamDynamic[x - 1][y + 1]);
if (minimum == seamDynamic[x - 1][y]) {
// add backtracker.
backtracker[x][y] = 1;
} else { // y + 1
// add backtracker.
backtracker[x][y] = 2;
}
} else if (y == (height - 1)) {
minimum = Math.min(seamDynamic[x - 1][y], seamDynamic[x - 1][y - 1]);
if (minimum == seamDynamic[x - 1][y]) {
// add backtracker.
backtracker[x][y] = 1;
} else { // y - 1
// add backtracker.
backtracker[x][y] = 0;
}
} else {
minimum = Math.min(seamDynamic[x - 1][y - 1], Math.min(seamDynamic[x - 1][y], seamDynamic[x - 1][y + 1]));
if (minimum == seamDynamic[x - 1][y - 1]) {
// add backtracker.
backtracker[x][y] = 0;
} else if (minimum == seamDynamic[x - 1][y]) {
// add backtracker.
backtracker[x][y] = 1;
} else { // y + 1
// add backtracker.
backtracker[x][y] = 2;
}
}
seamDynamic[x][y] = energyTable[x][y] + minimum;
}
}
}
// now that we have computed the paths, we need to backtrace the minimum one.
// 0 --> y - 1.
// 1 --> y.
// 2 --> y + 1.
// first we need to find the min at the end.
double min_num = seamDynamic[width - 1][0];
int min_index = 0;
for (int y = 0; y < height; y++) {
if (min_num > seamDynamic[width - 1][y]) {
min_index = y;
min_num = seamDynamic[width - 1][y];
}
}
// now that we have the min we need to backtrace it.
int y_index = min_index;
int x_index = width - 1;
seam[x_index][0] = x_index;
seam[x_index][1] = y_index;
int backtrack;
while (x_index > 0) {
backtrack = backtracker[x_index][y_index];
if (backtrack != -1) {
if (backtrack == 0) {
y_index = y_index - 1;
} else if (backtrack == 1) {
y_index = y_index;
} else { // = 2
y_index = y_index + 1;
}
} else {
y_index = y_index;
}
x_index = x_index - 1;
seam[x_index][0] = x_index;
seam[x_index][1] = y_index;
}
}
您可以在此处找到 Java 接缝雕刻机的完整代码。