Finish 2010-11-17 12:00:00 UTC

Lost Sailor Final3

by Andre Fioravanti

Status: Passed
Results: 3986 (cyc: 10, node: 2396)
CPU Time: 77.087
Score: 810.649
Submitted at: 2010-11-17 16:58:07 UTC
Scored at: 2010-11-17 18:42:55 UTC

Current Rank: 103rd (Highest: 87th )
Based on: Tweak that cyclical catbird (diff)

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Code
function [thrustRow, thrustCol] = solver(chart, aIndex, bIndex, maxThrottle)

[thrustRow, thrustCol] = nickelfelpeterv3(chart, aIndex, bIndex, maxThrottle);
score1 = runsolution(thrustRow, thrustCol, chart(:,:,2), chart(:,:,1), aIndex, bIndex);
if score1<15
  return
end


[thrustRow0, thrustCol0, score0] = nickelfelpeterv2(chart, aIndex, bIndex, maxThrottle);

if score0<score1,
    thrustRow=thrustRow0;
    thrustCol=thrustCol0;
end

end


function [thrustRow, thrustCol, score] = nickelfelpeterv2(chart, aIndex, bIndex, maxThrottle)
%REP
%by Gwendolyn Fischer
%r4537 t44

ONEHUNDRED = 100;
ONE        =   1;

y_winds         = chart(:,:,1);
x_winds         = chart(:,:,2);
[ny,nx]         = size(x_winds);
ay              = rem(aIndex-ONE, ny) + ONE;
ax              = (aIndex - ay)/ny  + ONE;
by              = rem(bIndex-ONE, ny) + ONE;
bx              = (bIndex - by)/ny  + ONE;
x               = (1:nx);
y               = (1:ny)';
X               = x(ones(ny,1),:);
Y               = y(:,ones(nx,1));
dist_to_B       = (X - bx).^2 + (Y - by).^2;
dist_to_A       = (X - ax).^2 + (Y - ay).^2;

maxIter         = 1034;
SDBiter         = [200 200];
INF             = 100000;
SDBzoom         = [INF 1/2];

dist_to_B_w     = dist_to_B*1e-4;
dist_to_A_w     = dist_to_A*1e-4;

y_dir           = 2*(by > ay) - ONE;
x_dir           = 2*(bx > ax) - ONE;
fuel            = Inf(ny,nx);
fuel(aIndex)    = 0;
fuel_to_reverse = fuel;
xvel            = zeros(ny,nx);
yvel            = zeros(ny,nx);
checked         = zeros(ny,nx);
previous_stop   = zeros(ny,nx);
min_fuel        = 0;
[cost_to_B cost_to_B_idx] = min(fuel_to_reverse(:) + dist_to_B(:));
zoon = nx*ny*SDBzoom.^2;

for i = 1:2
    
    SDB_tf = dist_to_B(:)<=zoon(i);
    SDB_idx = find(SDB_tf);
    
    SDBchecked = checked(SDB_tf);
    SDBfuel = fuel(SDB_tf);
    SDBdist_to_B_w = dist_to_B_w(SDB_tf);
    SDBdist_to_B = dist_to_B(SDB_tf);
    SDBxvel = xvel(SDB_tf);
    SDByvel = yvel(SDB_tf);
    SDBX = X(SDB_tf);
    SDBY = Y(SDB_tf);
    SDBprevious_stop = previous_stop(SDB_tf);
    
    it = 0;
    slowDown = maxThrottle+(SDBdist_to_B).^.77/4-3;
    while (  min_fuel <= cost_to_B  && ~all(SDBchecked) && it < SDBiter(i))
        it                      = it + 1;
        metrix                  = SDBfuel + SDBchecked + SDBdist_to_B_w;
        [dummy,i_p]              = min(metrix(:));
        i_p_full                = SDB_idx(i_p);
        min_fuel                = SDBfuel(i_p);
        i_y                     = rem(i_p_full - 1,ny) + ONE;
        i_x                     = (i_p_full - i_y)/ny  + ONE;
        i_vy                    = SDByvel(i_p) + y_winds(i_p_full);
        i_vx                    = SDBxvel(i_p) + x_winds(i_p_full);
        i_new_vy                = SDBY - i_y;
        i_new_vx                = SDBX - i_x;
        i_thrust                = abs(i_new_vx - i_vx) + abs(i_new_vy - i_vy);
        i_fuel                  = i_thrust + min_fuel;
        i_reacheable            = (i_thrust <= maxThrottle) & (abs(i_new_vy+y_winds(i_p_full))+abs(i_new_vx+x_winds(i_p_full))<slowDown);
        i_optimum               = i_fuel < SDBfuel;
        i_impr_tf               = i_reacheable & i_optimum;
        if ~any(i_impr_tf)
            SDBchecked(i_p)            = ONEHUNDRED; %true;
            continue;
        end
        i_impr_idx              = find(i_impr_tf);

        i_fuel_impr             = i_fuel  (i_impr_idx) ;
        SDBxvel           (i_impr_idx) = i_new_vx(i_impr_idx);
        SDByvel           (i_impr_idx) = i_new_vy(i_impr_idx);
        SDBfuel           (i_impr_idx) = i_fuel_impr;
        SDBprevious_stop  (i_impr_idx) = i_p_full;
        cost_to_B = min(cost_to_B,min(SDBfuel(i_impr_idx) + SDBdist_to_B(i_impr_idx)));
        SDBchecked(i_impr_idx)     = 0; %false;
        SDBchecked(i_p)            = ONEHUNDRED; %true;
   end
    
    fuel(SDB_tf) = SDBfuel;
    previous_stop(SDB_tf) = SDBprevious_stop;
    xvel(SDB_tf) = SDBxvel;
    yvel(SDB_tf) = SDByvel;
    
end

fuel                    = fuel + dist_to_B;
[cost_to_A cost_to_A_idx] = min(fuel(:) + dist_to_A(:));

checked                 = checked*0;
return_previous_stop    = zeros(ny,nx);

it                      = 0;
min_fuel                = 0;

while ( min_fuel < cost_to_A &&  ~all(checked(:)) && it < maxIter )
    
    it                  = it + 1;
    metrix              = fuel + checked + dist_to_A_w; %****
    [dummy,i_p]             = min(metrix(:)); %****
    min_fuel            = fuel(i_p); %****
    
    i_y                 = rem(i_p - 1,ny) + ONE;
    i_x                 = (i_p - i_y)/ny  + ONE;
    i_vy                = yvel(i_p) + y_winds(i_p);
    i_vx                = xvel(i_p) + x_winds(i_p);
    i_new_vy            = Y-i_y;
    i_new_vx            = X-i_x;
    i_thrust            = abs(i_new_vx - i_vx) + abs(i_new_vy - i_vy);
    i_fuel              = i_thrust + min_fuel;
    i_reacheable        = i_thrust <= maxThrottle;
    i_optimum           = i_fuel < fuel;
    i_impr_tf           = i_reacheable & i_optimum;
        if ~any(i_impr_tf)
            checked(i_p)            = ONEHUNDRED; %true;
        continue;
    end
    i_impr_idx          = find(i_impr_tf);

    fuel                (i_impr_idx) = i_fuel(i_impr_idx);
    xvel                (i_impr_idx) = i_new_vx(i_impr_idx);
    yvel                (i_impr_idx) = i_new_vy(i_impr_idx);
    return_previous_stop(i_impr_idx) = i_p;
    cost_to_A = min(cost_to_A,min(fuel(i_impr_idx) + dist_to_A(i_impr_idx)));
    %checked(i_impr_idx) = 0;
    checked(i_p)        = 100;
    checked(i_impr_idx) = 0;
end

cost_to_A           = fuel + dist_to_A;
[score,min_fuel]        = min(cost_to_A(:));
indices             = zeros(nx*ny,1);
indices(1)          = min_fuel(1);
[indices,k]         = while_go(indices, 1, return_previous_stop);
indices(k)          = previous_stop(indices(k-1));
[indices,k]             = while_go(indices, k, previous_stop);
indices = indices(k-1:-1:1);

ypos                = rem(indices - 1, ny) + 1;
xpos                = (indices - ypos)/ny + 1;

thrustCol           = diff([0; diff(xpos)]) - x_winds(indices(1:end-1));
thrustRow           = diff([0; diff(ypos)]) - y_winds(indices(1:end-1));

score = min((xpos-bx).^2 + (ypos-by).^2) + sum(abs(thrustCol))+sum(abs(thrustRow)) + (ypos(end)-ay).^2 + (xpos(end)-ax).^2;
end

function [thrustRow, thrustCol] = nickelfelpeterv3(chart, aIndex, bIndex, maxThrottle)
%continue
%by Sebastian Ullmann
%r4107 t50

y_winds         = chart(:,:,1);
x_winds         = chart(:,:,2);
[ny,nx]         = size(x_winds);
ay              = rem(aIndex-1, ny) + 1;
ax              = (aIndex - ay)/ny  + 1;
by              = rem(bIndex-1, ny) + 1;
bx              = (bIndex - by)/ny  + 1;
x               = (1:nx);
y               = (1:ny)';
X               = x(ones(ny,1),:);
Y               = y(:,ones(nx,1));

dist_to_B       = ((X - bx).^2 + (Y - by).^2).^1.15;
dist_to_A       = ((X - ax).^2 + (Y - ay).^2).^1.155;

dist_to_B_w     = dist_to_B*1e-4;
dist_to_A_w     = dist_to_A*1e-4;

fuel            = 100*ones(ny,nx);
fuel(aIndex)    = 0;
xvel            = zeros(ny,nx);
yvel            = xvel;
checked         = xvel;
previous_stop   = xvel;
min_fuel        = 0;
cost_to_B = dist_to_B(aIndex);
zoon = nx*ny*[10 0.37];
ziter = [500 700];% .* mxrand(-0.05);
sf = [0.31 0.19];

for i = 1:2
    
    SDB_tf = dist_to_B(:)<=zoon(i);
    SDB_idx = find(SDB_tf);
    
    SDBchecked = checked(SDB_tf);
    SDBfuel = fuel(SDB_tf);
    SDBdist_to_B_w = dist_to_B_w(SDB_tf);
    SDBdist_to_B = dist_to_B(SDB_tf);
    SDBxvel = xvel(SDB_tf);
    SDByvel = yvel(SDB_tf);
    SDBX = X(SDB_tf);
    SDBY = Y(SDB_tf);
    SDBprevious_stop = previous_stop(SDB_tf);
    
    slowdown = maxThrottle+SDBdist_to_B*sf(i);
    
    it = 0;
    
    while (  min_fuel < cost_to_B  && ~all(SDBchecked) && it < ziter(i))
        it                      = it + 1;
        metrix                  = SDBfuel + SDBchecked + SDBdist_to_B_w;
        [dummy,i_p]             = min(metrix);
        i_p_full                = SDB_idx(i_p);
        min_fuel                = SDBfuel(i_p);
        i_y                     = rem(i_p_full - 1,ny) + 1;
        i_x                     = (i_p_full - i_y)/ny  + 1;
        i_y_winds               = y_winds(i_p_full);
        i_x_winds               = x_winds(i_p_full);
        i_vy                    = SDByvel(i_p) + i_y_winds;
        i_vx                    = SDBxvel(i_p) + i_x_winds;
        i_new_vy                = SDBY - i_y;
        i_new_vx                = SDBX - i_x;
        i_thrust                = abs(i_new_vx - i_vx) + abs(i_new_vy - i_vy);
        i_fuel                  = i_thrust + min_fuel;
        i_impr_tf               = (i_thrust <= maxThrottle) & (abs(i_new_vy+i_y_winds)+abs(i_new_vx+i_x_winds)<slowdown) & (i_fuel < SDBfuel);
                if ~any(i_impr_tf)
            SDBchecked(i_p)            = 100; %true;
            continue;
        end
        i_impr_idx              = find(i_impr_tf);

        i_fuel_impr             = i_fuel  (i_impr_idx) ;
        SDBxvel           (i_impr_idx) = i_new_vx(i_impr_idx);
        SDByvel           (i_impr_idx) = i_new_vy(i_impr_idx);
        SDBfuel           (i_impr_idx) = i_fuel_impr;
        SDBprevious_stop  (i_impr_idx) = i_p_full;
        cost_to_B = min(cost_to_B,min(SDBfuel(i_impr_idx) + SDBdist_to_B(i_impr_idx)));
        SDBchecked(i_p)            = 100; %true;
        SDBchecked(i_impr_idx)     = 0; %false;
    end
    
    fuel(SDB_tf) = SDBfuel;
    previous_stop(SDB_tf) = SDBprevious_stop;
    xvel(SDB_tf) = SDBxvel;
    yvel(SDB_tf) = SDByvel;
    
end

fuel                    = fuel + dist_to_B;
cost_to_A               = min(fuel(:) + dist_to_A(:));

checked(:)                 = 0;
return_previous_stop    = checked;

it                      = 0;
min_fuel                = 0;

while ( min_fuel < cost_to_A &&  ~all(checked(:)) && it < min(nx*ny,2000))
    
    it                  = it + 1;
    metrix              = fuel + checked + dist_to_A_w; %****
    [dummy,i_p]             = min(metrix(:)); %****
    min_fuel            = fuel(i_p); %****
    
    i_y                 = rem(i_p - 1,ny) + 1;
    i_x                 = (i_p - i_y)/ny  + 1;
    i_vy                = yvel(i_p) + y_winds(i_p);
    i_vx                = xvel(i_p) + x_winds(i_p);
    i_new_vy            = Y-i_y;
    i_new_vx            = X-i_x;
    i_thrust            = abs(i_new_vx - i_vx) + abs(i_new_vy - i_vy);
    i_fuel              = i_thrust + min_fuel;
    i_impr_tf           = i_thrust <= maxThrottle & i_fuel < fuel;
            if ~any(i_impr_tf)
        checked(i_p)            = 100; %true;
        continue;
    end
    i_impr_idx          = find(i_impr_tf);

    fuel                (i_impr_idx) = i_fuel(i_impr_idx);
    xvel                (i_impr_idx) = i_new_vx(i_impr_idx);
    yvel                (i_impr_idx) = i_new_vy(i_impr_idx);
    return_previous_stop(i_impr_idx) = i_p;
    cost_to_A = min(cost_to_A,min(fuel(i_impr_idx) + dist_to_A(i_impr_idx)));
    checked(i_impr_idx) = 0;
    checked(i_p)        = 100;
    
end

cost_to_A           = fuel + dist_to_A;
[score,min_fuel]        = min(cost_to_A(:));
indices             = zeros(nx*ny,1);
indices(1)          = min_fuel(1);
[indices,k]         = while_go(indices, 1, return_previous_stop);
indices(k)          = previous_stop(indices(k-1));
[indices,k]             = while_go(indices, k, previous_stop);
indices = indices(k-1:-1:1);

ypos                = rem(indices - 1, ny) + 1;
xpos                = (indices - ypos)/ny + 1;

thrustCol           = diff([0; diff(xpos)]) - x_winds(indices(1:end-1));
thrustRow           = diff([0; diff(ypos)]) - y_winds(indices(1:end-1));

end

function [indices,k] = while_go(indices, k, return_previous_stop)
while(indices(k))
    k             = k + 1;
    indices(k)    = return_previous_stop(indices(k-1));
end
end

function score = runsolution(thrustRow, thrustCol, colWind, rowWind, aIndex, bIndex)
% RUNSOLUTION Simulates the navigation trajectory given the winds and the
% motor thrust.

[ny,nx]         = size(colWind);

AR              = rem(aIndex-1, ny) + 1;
AC              = (aIndex - AR)/ny  + 1;
BR              = rem(bIndex-1, ny) + 1;
BC              = (bIndex - BR)/ny  + 1;


% Initialize variables at start point (A)
fR = AR; fC =AC;
fvR = 0; fvC = 0;
dB = (fR-BR)^2 + (fC-BC)^2;

for i = 1:numel(thrustRow)
    ivR = fvR + thrustRow(i) + rowWind(fR,fC);
    ivC = fvC + thrustCol(i) + colWind(fR,fC);
    iR = fR + ivR;
    iC = fC + ivC;
    fR = iR;
    fC = iC;
    fvR = ivR;
    fvC = ivC;
    % Verify if this is the closest point to B
    dBtmp = (fR-BR)^2 + (fC-BC)^2;
    if  dBtmp < dB
        dB = dBtmp;
    end
end
dA = (fR-AR)^2 + (fC-AC)^2; % Final distance to A
score = dB + dA + sum(abs(thrustRow)) + sum(abs(thrustCol))+1;
end