Tontti

//import java.util.Random;

/**
 * Created by Frans on 5.10.2015.
 */
public class Tontti{

    static int height;
    static int width;
    static int[][] kenttaSumma;
    static int wantedTrees;

    static int lastSize;


    static long runAmountB;
    static long runAmountBU;
    static long runAmountBD;
    static long runAmountL;

    public static void main(String[] args){

        /*//todo
        int futureWidth = 2000;
        int futureHeight = 2000;
        int futureWantedTrees = (int) (2*Math.pow(10,2));
        height = futureHeight;
        width = futureWidth;
        wantedTrees = futureWantedTrees;

        kenttaSumma = new int[width+1][height+1];
        Random generator = new Random(1);

        String[] lines = new String[height+1];
        for (int y=1; y<=height; y++) {
            lines[y] = "";
            for (int x2=1; x2<=width; x2++){
                if (generator.nextDouble() > 0.3){
                    lines[y] = lines[y] + ".";
                }else {
                    lines[y] = lines[y] + "*";
                }
            }
        }
        kenttaSumma = new int[width+1][height+1];

        long aika = System.nanoTime();
        */


        IO io = new IO();


        height = io.nextInt();
        width = io.nextInt();
        wantedTrees = io.nextInt();
        kenttaSumma = new int[width+1][height+1];


        int foundArea = 0;
        int minSize = (int) (Math.sqrt(wantedTrees) + 0.99);

        //calculate trees and save it in to array and summed area table
        for (int y = 1; y <= height; y++) {
            final char[] line = io.next().toCharArray();
            //final char[] line = lines[y].toCharArray();

            int sumRow = 0;
            for (int x = 1; x <= width; x++) {
                if (line[x-1] == '*') {
                    sumRow++;
                }
                kenttaSumma[x][y] = sumRow + kenttaSumma[x][y - 1];

                int maxSize = min(x, y);

                //todo remove
                /*if (x==1999 && y==1999){
                    //stop here
                    break mainLoop;
                }*/

                if (maxSize >= minSize) {
                    foundArea += countAreasS(maxSize, minSize, x, y);
                }
            }

            lastSize = minSize;
        }

        io.println(foundArea);

        /*aika = (System.nanoTime()-aika)/1000000;
        io.println("---");
        io.println("Time: " + aika);
        io.println("Loops Binary: " + runAmountB/1000000.0);
        io.println("   -high: " + runAmountBU/1000000.0);
        io.println("   -low: " + runAmountBD/1000000.0);
        io.println("Loops Linear: " + runAmountL/1000000.0);
        */

        io.close();
    }

    //rekursiivinen binaarihaku
    // x2 = x -1
    // y2 = y -1
    private static int countAreasB(int maxSize,int minSize, int x, int y, int prevSize, double weight){
        int areasFound = 0;
        int tSize = (int) (((maxSize*(1.0+weight) + minSize*(1.0-weight))/2.0));

        //lopetaan kun sama on jo katsottu
        if (prevSize != tSize){
            prevSize = tSize;

            runAmountB ++;
            int sum = kenttaSumma[x][y]+kenttaSumma[x-tSize][y-tSize]-kenttaSumma[x][y-tSize]-kenttaSumma[x-tSize][y];

            if(sum > wantedTrees){
                runAmountBU ++;
                //tSize = (int) (Math.sqrt(tSize*tSize-(sum-wantedTrees))+0.999); //pitkalle johdettu matemaattinen optimointi

                areasFound += countAreasB(tSize, minSize, x, y, prevSize,0);
            }else if (sum < wantedTrees){
                runAmountBD ++;
                tSize = (maxSize - tSize == 1)?maxSize+1:tSize; //estetaan pyoristysvirhe
                areasFound += countAreasB(maxSize, tSize, x, y, prevSize,0);
            }else {
                //molemmat suunnat ovat mahdollisia --> kokeillaan kaikki lahella olevat
                areasFound ++;
                areasFound += countAreasL(tSize+1, maxSize, x, y, 1);
                areasFound += countAreasL(tSize-1, minSize, x, y, -1);
                lastSize = prevSize;
            }
        }
        
        return areasFound;
    }

    //rekursiivinen binaarihauen alku
    // x2 = x -1
    // y2 = y -1
    private static int countAreasS(int maxSize,int minSize, int x, int y){
        int areasFound = 0;
        int tSize = lastSize;
        //int tSize = min(max(lastSize,minSize),maxSize);
        int prevSize = tSize;

        runAmountB ++;
        int sum = kenttaSumma[x][y]+kenttaSumma[x-tSize][y-tSize]-kenttaSumma[x][y-tSize]-kenttaSumma[x-tSize][y];

        if(sum > wantedTrees){
            runAmountBU ++;
            //tSize = (int) (Math.sqrt(tSize*tSize-(sum-wantedTrees))+0.999); //pitkalle johdettu matemaattinen optimointi
            //tSize = (tSize - minSize <= 1)?minSize:tSize; //estetaan pyoristysvirhe

            areasFound += countAreasB(tSize, minSize, x, y, 0,0.75);
            //areasFound += countAreasD(tSize-1, minSize, x, y, -1);
        }else if (sum < wantedTrees){
            runAmountBD ++;
            tSize = (maxSize - tSize == 1)?maxSize+1:tSize; //estetaan pyoristysvirhe
            areasFound += countAreasB(maxSize, tSize, x, y, 0,-0.75);
            //areasFound += countAreasD(tSize+1, maxSize, x, y, 1);
        }else {
            //molemmat suunnat ovat mahdollisia --> kokeillaan kaikki lahella olevat
            areasFound ++;
            areasFound += countAreasL(tSize + 1, maxSize, x, y, 1);
            areasFound += countAreasL(tSize-1, minSize, x, y, -1);
        }

        return areasFound;
    }


    //suoraviivainen haku
    // x2 = x-1
    // y2 = y-1
    private static int countAreasL(int startSize,int endSize, int x, int y, int direction){
        int areasFound = 0;

        for (int tSize=startSize; direction*tSize<=endSize*direction; tSize=tSize+direction){

            runAmountL ++;
            int sum = kenttaSumma[x][y]+kenttaSumma[x-tSize][y-tSize]-kenttaSumma[x][y-tSize]-kenttaSumma[x-tSize][y];
            if (sum == wantedTrees){
                areasFound ++;
                lastSize = tSize;
            }else{
                break;
            }

        }

        return areasFound;
    }

    //suoraviivainen haku, hidas ja turha
    // x2 = x-1
    // y2 = y-1
    private static int countAreasD(int startSize,int endSize, int x, int y, int direction){
        int areasFound = 0;

        for (int tSize=startSize; direction*tSize<=endSize*direction; tSize=tSize+direction){

            runAmountL ++;
            int sum = kenttaSumma[x][y]+kenttaSumma[x-tSize][y-tSize]-kenttaSumma[x][y-tSize]-kenttaSumma[x-tSize][y];
            if (sum == wantedTrees){
                areasFound ++;
                lastSize = tSize;
            }else if (areasFound > 0){
                break;
            }

        }

        return areasFound;
    }

    //just for lulz
    private static int max(final int a, final int b){
        return (a>b)?a:b;
    }
    private static int min(final int a, final int b){
        return (a<b)?a:b;
    }


}

Test 1

Group: 1

Verdict: ACCEPTED

Test 2

Group: 1

Verdict: ACCEPTED

Test 3

Group: 1

Verdict: ACCEPTED

Test 4

Group: 1

Verdict: ACCEPTED

Test 5

Group: 1

Verdict: ACCEPTED

Test 6

Group: 2

Verdict: ACCEPTED

Test 7

Group: 2

Verdict: ACCEPTED

Test 8

Group: 2

Verdict: ACCEPTED

Test 9

Group: 2

Verdict: ACCEPTED

Test 10

Group: 2

Verdict: ACCEPTED

Test 11

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 12

Group: 3

Verdict: TIME LIMIT EXCEEDED

Test 13

Group: 3

Verdict: ACCEPTED

Test 14

Group: 3

Verdict: ACCEPTED

Test 15

Group: 3

Verdict: ACCEPTED