有
N
N条绳子，它们的长度分别为
L
i
L
i
。如果从它们中切割出
K
K条长度相同的绳子的话，这
K
K条绳子每条最长能有多长?答案保留到小数点后恰好2位(直接舍掉 2 位后的小数)。
#include<bits/stdc++.h>
using namespace std;
int n,k;
double a[10010],l=1e-10,r=1e9;
int check(double lon){
int sum=0;
for(int i=0;i<n;i++) sum+=double(a[i]/lon);
return sum;
}
int main(){
cin>>n>>k;
for(int i=0;i<n;i++) cin>>a[i];
while(l+0.001<r){
double mid=(l+r)/2.0;
if(check(mid)>=k) l=mid;
else r=mid;
}
cout<<fixed<<setprecision(2)<<l<<endl;
return 0;
}
错误测试点：#6
1988 7481
76045.1 79026.5 5822.41 37767 32616.1 55582.9 16187.7 10864.4 19071.4 57724.7 27343 23996.1 13154.8 47541.3 74739.4 66903.7 3345.6 67297 83954.3 98194.2 98339 55217.4 86806 42376.8 81590.3 46597.4 31288.1 76021.2 56254.4 34621.1 63050.3 50630.9 15995.6 14979.5 37736.7 908.37 95929 95313.2 18575 36944.5 3165.14 78608.6 97619.8 48089.3 88459.1 89557.4 72094.2 14999.1 88206.1 68409.6 7347.88 72109.6 57989.4 74464.9 81746.7 80538.5 49510.3 4648.24 2403.95 3853.37 76116.7 73626.1 38505.1 85519.8 51820.1 38862.6 53314.3 37573 91675.8 25131.6 40184.4 38659.8 99197.6 84446.1 51075.7 5713.08 78400.8 16854.5 2713.52 71939.9 92847.5 92742.2 94154.2 98527.2 92836.1 14278.9 55495.1 7399.21 17656.1 45616.6 74336.3 41039.8 91619 95033.8 27210.7 82508.9 23352.8 18636.9 82561.6 71268.9 3192.54 8028.69 97134.4 2367.29 27378.2 56750.9 95284.9 16317.6 11176.4 50283.4 15554.1 78173.7 11015.1 74790.3 32531.3 1955.85 19019.3 41564.2 18037.1 39094.1 4972.42 9929.42 9449.81 60210.8 67455.6 47204.6 36228.1 43088.8 17551.2 52020.7 5271.96 18934.8 92488.4 52085.8 72537.2 71547.9 61530.3 6351.22 37220.4 59444 32948.5 53039.5 52335.7 46036.2 79492.8 91459.4 81324.1 59242.2 63959.8 97076.7 70946.6 79361.3 71651.8 71139.9 17086.7 48286.7 45223.5 41929.2 43908.1 34227.2 22207.2 99007 75958.5 94807.5 35095.4 67405.3 71542.9 25461.3 49915.5 60525.7 49259 25105.2 48903.1 63883.1 83850.6 43864.9 11741.7 8607.5 66913.9 87640.1 67381.6 70720.5 91422.1 92182.4 58326.1 93672.4 18742.5 30083.5 75942.7 4801.77 32755 5702.54 23890.6 7630.96 19173.7 63307.6 6507.33 37450.3 86962.3 11511.5 48457.7 87621.8 56042.7 44363.4 18017.9 4811.68 50264.6 70489.2 74860.2 23264.3 81026.3 99388.1 74675.7 45552.7 29823.4 47518.8 75887.2 10767.9 46241.4 3806.14 98373.6 58686.4 7531.14 17922.6 42766.9 32125.6 24970 23055.8 25040.4 82677 89527.8 4307.82 30988 90799.3 80842.4 37445.9 89333 79717.1 42919.1 46045.4 78383.6 96371.3 85543.4 41717.8 93642.8 63810.3 9425.45 3877.59 45029.7 90940.3 69780.3 12810 22215.4 8140.41 78750.9 44147.5 40419 18240 33033.1 85353.9 76104.5 90259.3 96482.7 52487.1 95565.3 32999 43652.6 2053.15 292.93 19236.7 44376.1 34576.3 55424.8 93437 77664 52388.3 32743.3 68601.6 55341.1 96971.3 82592.6 59499.6 86131.9 26586.9 97758.6 76033 26325.5 59261.8 45394.1 81694.5 24569.4 6310.06 6907.97 63918.7 21440.5 34854.4 52558.2 76273.4 59540.6 6966.64 61684.8 81629.2 12997.7 33234.7 92435.6 31685.6 67462.3 48363 62674.6 19350 57096.8 32303.3 36873.5 22644.3 87744.6 25021.1 56767.1 41822.1 89104.7 40338.6 76789.1 82313.1 64823.7 42246.2 2108.06 5539.99 35571.1 1157.61 88696.2 6357.42 33120.2 77437.5 57592.6 4981.51 32357.1 98408.9 63594.1 9479.46 8390.45 30154.5 95582 90515.1 90199 74084.1 41930 34571.5 71800.7 19776.6 30846 73385.5 21165.4 6743.83 11366.2 94373.6 39151 98450.6 32321.8 78197.2 10103.4 36238.3 12882.5 78094.7 56645.6 45264.2 27462.6 98207 29167.2 82988 67314.9 97092.4 31307.4 72671.6 51518.7 34443.1 83544.5 18876.3 29517 20564.4 52192.6 29234.7 46177 26810.8 34600.4 18434.6 96606.5 46831.4 97145.4 8056.76 79098.5 72658.2 45423.2 40506.8 50930.2 88116.8 48715.7 78365.5 21171.9 1869.38 22947.5 64753.1 98422.2 39181.8 3798.95 82157.4 45618.8 25021.4 88346.7 3498.57 2280.84 94733.1 61925.8 23306 82288.5 61248.7 53493.4 9967.57 36765.2 92058.4 91631.9 26241 77430.2 24918.6 3091.59 3411.24 63817.7 19312.2 71868.1 38915.3 23411.2 72431.5 59717.1 25958.8 41083.3 25361.1 31511.9 34443.6 44632.3 29145.9 93047.8 78319.4 34510.8 33779.6 65351.5 81341.9 69008.9 93864.8 18923 31.51 93384.1 35487.6 21790.7 41796.2 94483.1 44266.7 28800 35244.9 77130.5 6101.86 47954.4 50702 15501.9 96325.9 4585.06 89034.1 44507 93022.1 66843.8 73598.8 98984.2 92692.5 3431.45 7758.04 48158.3 97611.2 15731.2 92108.8 5489.02 24569.9 25959.2 18705.8 20716.8 55636.1 63531.6 98630.9 23439.1 6084.92 96181 33164.2 5316.41 41075.3 88180.4 14945.9 1997.8 26094.8 68040.5 99784.2 10436.1 63905.2 49370.1 14918.3 63391.3 14202.6 38642 89772.3 67488.9 51166.7 67820.2 15225.7 98211.4 38427.3 83781.5 21173 29715.4 44935.9 23150.1 41251.3 11550.2 98855.1 26986.4 17830.3 82132.3 85199.6 6263.11 30905.2 56130.8 87104.5 53097 98915.3 23960.4 80924.3 25768 87757 29271.8 33120.1 81825.1 66284 38679.3 29915.6 83445.6 64112.8 31903.6 14058.9 13582.2 14020.8 59327.2 73381.9 20295 85677.4 3396.83 19879.7 27493.9 37914.5 76235.6 21208.1 99755.9 4290.83 16333.5 19780.5 34735.2 18384.3 83325.8 46954.8 30598.3 83452.4 75441.1 96774.9 11316.1 41055.7 43413.3 15537.8 94768.1 38659.4 4675.89 43030.2 45209.1 57720.8 40178.1 26490.2 32353.1 17422.5 69197.8 10352.4 16648.2 29462.3 31555 23408.1 15096.4 21724.7 73348.4 44005.9 10620.9 53928.2 85861.5 70977.8 14892.5 3551.54 65958.8 15223.2 2053.2 82106.1 55050.8 7470.88 5679.47 6465.56 49611.7 39214.4 69575.9 8647.39 27429.1 70510.4 22255.1 20794.7 43936.2 54652.5 12538.8 4729.02 36736.4 94138.7 13916.1 58197.6 16072.1 32742.5 64783 97285.4 58139.6 51706.4 26025.3 52666.8 10749.2 57144.3 71734.3 3061.34 64718.4 37124 59244.7 19233.6 80389.7 42460 31731.8 21860.5 58317.3 44237.4 50165.2 62467.2 9522.5 13198.2 4725.49 8624.11 98208.6 836.17 12398.6 54400.1 22238.3 34814 81807.1 70890.8 91879.3 19596.2 26936.4 98495.4 41939.8 64884.9 65906.4 54991.5 33297.2 48649 90384.2 53655.3 47579.5 46894.8 95206.3 79368.9 31206.2 70417.5 95192.2 75192 44451.9 83205.9 40412.7 69107.3 20861.9 57377.6 30658.5 15562.8 40739.9 11955.4 62498.8 6244.86 70579.3 73017.2 36254.1 1902.1 78662 55797.3 60544.3 53861.4 62399.4 61262.9 45860.7 33150.3 94188.5 39156.4 27020.8 99009 16980.2 43332.3 56546.8 50736.8 36188.9 16527.8 56372.8 92072.2 33005.3 50566.7 85252 1234.68 7043.75 85929.9 75816.4 28679.2 8948.88 23790.7 43431.9 29483.3 17191.8 73249.9 41699.5 37197.4 2124.97 43317.3 74140.9 9202.03 59971.6 81905.2 52061.7 17120.4 87417.4 4988.06 83869.3 16848.7 85189.7 88422.3 8092.04 23630.3 66741.9 92006.2 92408.8 19335.6 4657.64 97135.1 35487.1 89484.3 83720.8 31143 49782.5 89091.2 83910.5 2980.31 67676.4 79651.1 81635.4 81929.6 2458.61 88585 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26814.3 79547.4 62670.2 42016.8 36071.1 11597.6 87939.8 72587.9 60637.3 48602.3 83464.1 56664.2 1834.78 58613.6 71702.2 44912.2 16282.2 33632 63816.2 96910.4 10952.4 13434.8 21685.5 59242.6 80531 71013.5 80492.1 38277.9 56553.7 47328.5 80502.3 48663.3 61144 90920 71936.9 28850.4 30216.3 42167.5 10545.9 63264.5 80065.9 80418.7 5351.8 63377.5 19608 44789 40671.5 63923.1 63897.3 91725.9 24108.9 40945.8 18235.5 97110.6 79641.5 650.95 44864 49686.7 76022.5 58369.3 54790.6 66727.3 77223.9 54358.4 28760.3 41045.3 84203.5 41283.2 9052.05 37049.1 55656.9 48356.6 44122.8 71357.4 26546.1 79406.6 67325.7 44828.2 94986.8 48991.8 81448.4 22294.4 95802.4 19338.4 50236.3 26210.6 87474.4 80344.6 96708.3 84149.3 40552 10824.5 40097.5 64024.6 31844.8 94083.6 92805.1 36457.3 86628.3 99910.9 46578.5 21045.5 73961.5 66464.4 45937.6 68101.9 14880 34491.5 16271.9 18228.7 41860.3 43013.2 75437.3 74158.9 74114 72650.7 85995.7 29599.5 38120.2 82425.2 18153.3 72387.3 45407.9 82316.6 6241.46 81275.7 75225.2 95185.3 320.27 49415 19916.1 57046.6 87289 64125.9 474.6 59826.2 94613 4657.25 90127.6 30409.7 78540.5 75752.2 47382.9 4719.35 43550.3 8226 47432.2 44267.7 2956.68 94965.6 23599 68697.1 1382.87 47361.3 11198.8 3698.31 86572.2 25441.7 39241.5 64971.8 90131.4 31542.8 38084.7 72647.2 77415.2 99278 18166.6 58078.3 27305.6 57972.6 97987.9 73132.8 76784.4 31505 48420.5 1728.18 67209 77253 62700.3 27633.8 72514.6 52191.2 70654.4 18883 54228.6 78951.1 6658.98 78712.8 77192.8 19129.5 69066.9 39003.5 91669 78308.8 87172.6 76789.6 29871.8 52104.9 19676.8 63438.4 17827.1 30864.7 42008.6 42675.7 25945.6 71484.3 76862.4 37244.2 735.73 43093.9 40473.3 30468.2 75766.9 22719.4 66118.4 30486.3 82603.3 76553.6 93894.5 35523.4 78416.1 97780.2 30360.9 84288.8 37638.9 44883 31002.3 94312.9 44969 17574.3 81616.3 36684.1 87673.2 56308.1 72679.9 66963.4 99477.6 98350.8 85272.4 67744.1 67431.1 14194.9 32945 78471.3 627.35 44492.7 41873.9 18652.6 9762.92 2261.05 12771.7 49936.1 83325.8 52303.9 24422.1 58761.3 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31802.9 20975.2 17585.1 35679.8 75097 7616.84 68868.9 96276 16889.4 60936.3 38747.9 11972.6 58112.7 26732.3 3092.42 69755.5 27135.9 63818.7 98416 27764 91543.3 40014.5 93816.4 71828.3 34441.9 48162.8 53635.5 6571.59 56547.2 60091.9 76406.8 58840.8 12046.8 91253.9 9321.21 93034.1 16891.9 75990.4 81314.7 78543.6 37191.7 98874.9 16490.6 32021.1 36437.7 83700.9 36123.7 26198.7 95804.5 97196.9 19270 84573 85146.2 14899.1 11122.3 37829.5 79765.8 32599 40785.6 88620.4 38870.1 47353.8 92898.2 34149.6 45103.9 71537.8 22961 1128.41 89206.6 81777.4 8762.82 10359.2 73076.6 95432.6 95175.1 6636.25 62158.9 24839.7 41151.3 17130.4 96884.8 99058.6 53738.7 89299.9 40329.7 41172.6 1865.41 63744.5 66101.1 17541.2 55022 2568.79 27955.8 91714.3 84608.2 33732.7 91264.1 51302 33550.3 86404.3 146.79 94943.3 56388.9 67916.8 84089.1 66735.3 25830.7 83150.6 41282.7 1734.59 64954.9 84442.9 55549.8 69336.6 92146 71980.6 94738.1 60037.6 96369.5 31665.6 44405.4 53241.7 40245.5 47452.2 71459.6 85657.6 63326 57883.9 76772 36857.4 2208.34 13619 49536.5 21929.8 86877.8 23704.8 17918.9 71309.2 77889 32890.3 12245.5 67499.7 76651.2 71368.9 17447.6 2263.79 83165.7 49848.4 62548 77610.4 49214.5 79432.6 82084 15991.6 99424.9 71486.4 63481.1 34081.8 53030.6 71599.7 48471 40043.6 90969.7 3267.06 88031 94379 95037.1 4968.54 1026.67 84825.9 4815.02 83676.7 97734.9 20680.5 79550.9 18537.6 15967.5 46423.3 53019.3 6444.33 68768.6 13514.1 95995.3 89748.4 58532.2 23349.3 12200 84894 93034.8 75303.1 74317.9 54664.4 86084.1 94828.5 54599.9 95452.9 16982.6 71101.3 59802.6 92271.9 25697.3 45.24 3594.91 69751.7 58822.6 62095.3 2416.24 46579.4 1067.44 20519.1 62856.9 53446.5 97951 60562.2 7161.03 28008.8 71909.9 55814.7 6526.59 67034.4 73977.3 33191.4 34222 43374.3 53938.2 99902 59010.6 52903.6 33144.7 20002.5 48674.4 27329.4 95733 45792 71095.9 75512.9 54796.4 94507.2 67692.7 87446.2 9412.27 78914.8 94605.6 29981.4 65667 43276.3 94144.2 34896.6 33726.3 39968.8 88119.3 15101.2 4663.27 88246.6 61273.6 38306 20648.5 84598.5 71463.8 31590.3 31409.4 28715.8 47653.8 4818.25 13857 38230.8 19929.2 17479.2 94980.5 68232.2 72187.4 16386.1 80052.9 85040 93287.4 47427.4 71398.9 17971.9 23498.9 65776.4 36520.9 58962.4 54366.2 8328.38 99484.3 85455 51089.2 85181.8 58904.1 98243.4 76721.8 40116.5 56867.9 84311.5 63366.8 35372 69723.6 47856.9 30022.5 54070.4 95134.9 86953.6 54997.1 35154.5 33229.3 17938 55740 83939.6 15510.8 36063.4 14972.4 70234.6 92679.6 35304.9 76411.7 3441 41775.4 52819.8 96642.4 28083 14522.1 24232 25635.8 90186 192.16 74609.7 22267.6 88677 32109.3 45983.6
ans：
11953.66
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