pragma solidity ^0.4.23;

library StringUtils {

function concat(

string _s1, string _s2,

string _s3, string _s4,

string _s5

) internal pure returns (string) {

bytes memory _b1 = bytes(_s1);

bytes memory _b2 = bytes(_s2);

bytes memory _b3 = bytes(_s3);

bytes memory _b4 = bytes(_s4);

bytes memory _b5 = bytes(_s5);

string memory concatString = new string(_b1.length +

_b2.length + _b3.length + _b4.length + _b5.length);

bytes memory concatBytes = bytes(concatString);

uint k = 0;

uint i;

for (i = 0; i < _b1.length; i++) concatBytes[k++] = _b1[i];

for (i = 0; i < _b2.length; i++) concatBytes[k++] = _b2[i];

for (i = 0; i < _b3.length; i++) concatBytes[k++] = _b3[i];

for (i = 0; i < _b4.length; i++) concatBytes[k++] = _b4[i];

for (i = 0; i < _b5.length; i++) concatBytes[k++] = _b5[i];

return string(concatBytes);

}

function concat(

string _s1, string _s2,

string _s3, string _s4

) internal pure returns (string) {

return concat(_s1, _s2, _s3, _s4, "");

}

function concat(

string _s1, string _s2,

string _s3

) internal pure returns (string) {

return concat(_s1, _s2, _s3, "", "");

}

function concat(

string _s1, string _s2

) internal pure returns (string) {

return concat(_s1, _s2, "", "", "");

}

function addressToString(address x) internal pure returns (string) {

bytes memory s = new bytes(40);

for (uint i = 0; i < 20; i++) {

byte b = byte(uint8(uint(x) / (2**(8*(19 - i)))));

byte hi = byte(uint8(b) / 16);

byte lo = byte(uint8(b) - 16 * uint8(hi));

s[2*i] = char(hi);

s[2*i+1] = char(lo);

}

return string(s);

}

function char(byte b) private pure returns (byte c) {

if (b < 10) return byte(uint8(b) + 0x30);

else return byte(uint8(b) + 0x57);

}

function uintToString(uint v) internal pure returns (string) {

uint maxlength = 78;

bytes memory reversed = new bytes(maxlength);

uint i = 0;

while (v != 0) {

uint remainder = v % 10;

v = v / 10;

reversed[i++] = byte(48 + remainder);

}

bytes memory s = new bytes(i);

for (uint j = 0; j < i; j++) {

s[j] = reversed[i - j - 1];

}

return string(s);

}

}