Add 2021 advent - day 7.

2021/day7/p.rkt

@@ -0,0 +1,20 @@
+#lang racket/base
+(require racket/string)
+
+(define (make-line t)
+  (map string->number (string-split t ",")))
+
+(define slist (make-line (read-line)))
+(define maxv (apply max slist))
+
+; part 1
+(apply min (for/list ([v (in-range maxv)])
+             (for/sum ([s (in-list slist)])
+               (abs (- v s)))))
+
+; part 2
+(apply min (for/list ([v (in-range maxv)])
+             (for/sum ([s (in-list slist)])
+               (define steps (abs (- v s)))
+               (/ (* (+ steps 1) steps) 2))))
+;(for/sum ([i (in-range (add1 steps))]) i))))

2021/day7/test1.txt

@@ -0,0 +1 @@
+16,1,2,0,4,2,7,1,2,14

2021/day7/test2.txt

@@ -0,0 +1 @@
+1101,1,29,67,1102,0,1,65,1008,65,35,66,1005,66,28,1,67,65,20,4,0,1001,65,1,65,1106,0,8,99,35,67,101,99,105,32,110,39,101,115,116,32,112,97,115,32,117,110,101,32,105,110,116,99,111,100,101,32,112,114,111,103,114,97,109,10,720,75,471,1142,1442,166,896,138,61,643,1331,315,365,43,4,289,577,1249,30,53,117,956,28,385,27,168,92,110,127,331,27,93,730,122,27,19,1563,708,849,190,1620,1135,878,74,60,424,500,10,7,1687,375,159,566,228,1069,1603,194,463,387,2,890,1060,600,27,578,66,91,510,383,827,1485,18,30,500,0,386,1088,1259,136,1013,660,748,1115,53,22,726,270,29,573,95,5,87,1467,95,1087,27,145,1264,12,621,549,1078,22,243,986,738,64,75,243,47,381,475,565,183,33,645,1,221,11,698,1415,77,269,1,61,67,219,1543,860,1352,338,292,42,2,962,97,282,132,1147,375,479,59,538,617,328,167,1414,365,185,364,553,407,807,226,1698,427,569,448,1549,957,192,906,101,21,31,224,715,890,992,1319,40,663,1094,1647,273,76,268,554,9,18,446,204,61,480,187,1260,131,272,1290,298,199,632,19,95,62,90,46,30,255,165,464,816,405,215,762,197,555,270,306,291,777,122,6,594,1073,231,3,198,790,902,747,908,202,33,56,412,615,437,60,978,418,1871,882,794,32,91,1620,119,16,327,1091,487,1934,1,114,880,32,709,213,127,92,360,30,897,975,75,651,818,87,626,397,927,90,128,129,141,112,1059,609,590,835,76,1707,791,310,328,1937,2,257,646,1150,823,181,5,31,925,321,75,75,167,12,571,340,62,434,107,619,255,923,357,537,507,1044,110,408,1015,616,711,28,322,435,556,27,3,932,1430,218,1227,429,209,735,106,1388,20,17,778,865,1578,847,150,268,1256,208,50,739,268,9,1242,1044,33,895,675,913,68,40,973,256,1314,531,101,709,291,176,211,757,535,31,9,618,121,770,868,1264,1829,68,318,697,51,64,89,27,240,975,586,27,149,142,547,25,168,393,81,1009,924,58,75,1007,675,73,286,598,212,686,431,274,75,1383,270,586,63,419,190,88,1005,222,169,403,440,385,474,697,1303,205,21,978,266,164,42,25,1687,150,235,422,1699,1323,63,260,1366,136,824,378,21,243,330,611,919,305,369,175,596,65,145,837,277,333,974,772,259,1445,19,20,73,253,9,77,329,466,584,216,39,406,299,446,91,1466,1981,307,755,168,245,236,73,103,149,754,106,195,95,147,84,378,230,588,27,953,876,1495,1794,1,15,176,895,1304,888,1174,444,4,978,14,614,1307,291,454,313,908,206,863,170,1360,85,720,605,38,1071,1137,833,356,1490,39,1531,142,109,93,392,12,1887,301,888,344,411,11,202,909,189,245,614,39,140,63,363,590,872,328,30,1627,1329,17,60,961,105,176,771,1119,23,1107,796,446,617,215,298,203,844,0,369,694,125,413,1412,167,95,858,1190,53,1238,83,126,482,2,93,1838,109,342,15,89,280,187,73,129,23,487,555,168,502,175,43,228,109,1170,1208,296,104,243,99,344,107,917,506,1434,1013,566,615,351,18,265,1152,585,1802,347,39,274,27,825,170,409,10,1159,43,10,1139,53,46,283,706,152,1804,863,797,31,141,351,131,242,1014,1617,228,258,739,336,665,409,1398,0,77,168,1376,464,135,1122,219,13,33,315,174,387,186,814,374,7,712,174,10,752,74,660,139,844,478,318,1866,26,307,82,87,1036,696,411,109,6,423,651,7,410,95,1600,134,203,273,37,81,151,320,1043,59,1074,1166,741,1040,155,534,972,1157,167,27,688,63,94,168,808,265,1791,328,781,403,1177,818,422,0,101,1483,67,1098,1679,148,546,1224,117,188,376,886,226,3,132,114,44,479,29,16,43,472,175,335,77,17,1252,468,390,71,111,728,1167,822,57,30,620,81,945,379,362,731,22,709,1428,1588,681,30,930,48,64,819,21,1179,907,1969,537,98,545,1303,217,1234,713,39,929,37,50,949,165,164,702,1706,1133,935,438,298,565,661,1133,762,1501,179,74,793,323,20,260,1396,204,421,654,699,64,1080,119,171,1217,652,11,13,298,302,1569,841,142,428,1535,159,538,381,1,721,59,12,297,421,126,9,91,1549,361,941,159,273,132,51,576,1247,754,18,105,355,500,121,714,264,363,27,515,109,359,57,1237,85,541,407,71,150,60,1089,125,462,214,76,21,1,865,605,1054,36,1332,687,1023,1012,961,298,537,1519,1644,971,93,596,289,355,526,359,348,706,232,133,523,95,723,489,1061,646,769,158,150,699,759,355,97,447,737,140,98,12,235,238,1175,705,65,158,204,164,109,1150