Where do you see a contradiction? There is none.
Matthew 21:18-21 KJV
18) Now in the morning as he returned into the city, he hungered.
19) And when he saw a fig tree in the way, he came to it, and found nothing thereon, but leaves only, and said unto it, Let no fruit grow on thee henceforward for ever. And presently the fig tree withered away.
20) And when the disciples saw it, they marvelled, saying, How soon is the fig tree withered away!
21) Jesus answered and said unto them, Verily I say unto you, If ye have faith, and doubt not, ye shall not only do this which is done to the fig tree, but also if ye shall say unto this mountain, Be thou removed, and be thou cast into the sea; it shall be done.
Mark 11:12-23 KJV
12) And on the morrow, when they were come from Bethany, he was hungry:
13) And seeing a fig tree afar off having leaves, he came, if haply he might find any thing thereon: and when he came to it, he found nothing but leaves; for the time of figs was not yet.
14) And Jesus answered and said unto it, No man eat fruit of thee hereafter for ever. And his disciples heard it.
15) And they come to Jerusalem: and Jesus went into the temple, and began to cast out them that sold and bought in the temple, and overthrew the tables of the moneychangers, and the seats of them that sold doves;
16) And would not suffer that any man should carry any vessel through the temple.
17) And he taught, saying unto them, Is it not written, My house shall be called of all nations the house of prayer? but ye have made it a den of thieves.
18) And the scribes and chief priests heard it, and sought how they might destroy him: for they feared him, because all the people was astonished at his doctrine.
19) And when even was come, he went out of the city.
20) And in the morning, as they passed by, they saw the fig tree dried up from the roots.
21) And Peter calling to remembrance saith unto him, Master, behold, the fig tree which thou cursedst is withered away.
22) And Jesus answering saith unto them, Have faith in God.
23) For verily I say unto you, That whosoever shall say unto this mountain, Be thou removed, and be thou cast into the sea; and shall not doubt in his heart, but shall believe that those things which he saith shall come to pass; he shall have whatsoever he saith.
Both accounts are complementary, not contradictory. Again you needlessly cast doubt on the Bible.
