Project Euler 11

正規表現で表を作りなおすのに時間がかかった．
ちょっと無駄なものが入っている．

#include <iostream>
#include <cstdio>
#include <algorithm>
int main(){
	int map[20][20] = {{8,2,22,97,38,15,0,40,0,75,4,5,7,78,52,12,50,77,91,8},
										 {49,49,99,40,17,81,18,57,60,87,17,40,98,43,69,48,4,56,62,0},
										 {81,49,31,73,55,79,14,29,93,71,40,67,53,88,30,3,49,13,36,65},
										 {52,70,95,23,4,60,11,42,69,24,68,56,1,32,56,71,37,2,36,91},
										 {22,31,16,71,51,67,63,89,41,92,36,54,22,40,40,28,66,33,13,80},
										 {24,47,32,60,99,3,45,2,44,75,33,53,78,36,84,20,35,17,12,50},
										 {32,98,81,28,64,23,67,10,26,38,40,67,59,54,70,66,18,38,64,70},
										 {67,26,20,68,2,62,12,20,95,63,94,39,63,8,40,91,66,49,94,21},
										 {24,55,58,5,66,73,99,26,97,17,78,78,96,83,14,88,34,89,63,72},
										 {21,36,23,9,75,0,76,44,20,45,35,14,0,61,33,97,34,31,33,95},
										 {78,17,53,28,22,75,31,67,15,94,3,80,4,62,16,14,9,53,56,92},
										 {16,39,5,42,96,35,31,47,55,58,88,24,0,17,54,24,36,29,85,57},
										 {86,56,0,48,35,71,89,7,5,44,44,37,44,60,21,58,51,54,17,58},
										 {19,80,81,68,5,94,47,69,28,73,92,13,86,52,17,77,4,89,55,40},
										 {4,52,8,83,97,35,99,16,7,97,57,32,16,26,26,79,33,27,98,66},
										 {88,36,68,87,57,62,20,72,3,46,33,67,46,55,12,32,63,93,53,69},
										 {4,42,16,73,38,25,39,11,24,94,72,18,8,46,29,32,40,62,76,36},
										 {20,69,36,41,72,30,23,88,34,62,99,69,82,67,59,85,74,4,36,16},
										 {20,73,35,29,78,31,90,1,74,31,49,71,48,86,81,16,23,57,5,54},
										 {1,70,54,71,83,51,54,69,16,92,33,48,61,43,52,1,89,19,67,48}};

	//x direction
	int xmax = 0, xx = 0, xy = 0;
	for(int i=0;i<20;i++){
		for(int j=0;j<=20-4;j++){
			if(map[i][j] * map[i][j+1] * map[i][j+2] * map[i][j+3] > xmax)xx = j, xy = i;
			xmax = std::max(xmax, map[i][j] * map[i][j+1] * map[i][j+2] * map[i][j+3]);
		}
	}
	printf("X: %d (%d,%d)\n", xmax, xx, xy);

	//y direction
	int ymax = 0, yx = 0, yy = 0;
	for(int i=0;i<20;i++){
		for(int j=0;j<=20-4;j++){
			if(map[j][i] * map[j+1][i] * map[j+2][i] * map[j+3][i] > ymax)yx = i, yy=j;
			ymax = std::max(ymax, map[j][i] * map[j+1][i] * map[j+2][i] * map[j+3][i]);
		}
	}
	printf("Y: %d (%d,%d)\n", ymax, yx, yy);

	//naname direction
	int smax = 0, sx = 0, sy = 0;
	for(int i=0;i<=20-4;i++){
		for(int j=0;j<=20-4;j++){
			if(map[i][j] * map[i+1][j+1] * map[i+2][j+2] * map[i+3][j+3] > smax)sx = j, sy = i;
			smax = std::max(smax, map[i][j] * map[i+1][j+1] * map[i+2][j+2] * map[i+3][j+3]);
		}
	}
	printf("S: %d (%d,%d)\n", smax, sx, sy);

	//reverse naname direction
	int rsmax = 0, rsx = 0, rsy = 0;
	for(int i=3;i<20;i++){
		for(int j=0;j<=20-4;j++){
			if(map[i][j] * map[i-1][j+1] * map[i-2][j+2] * map[i-3][j+3] > rsmax)rsx = j, rsy = i;
			rsmax = std::max(rsmax, map[i][j] * map[i-1][j+1] * map[i-2][j+2] * map[i-3][j+3]);
		}
	}
	printf("RS: %d (%d,%d)\n", rsmax, rsx, rsy);
}