mirror of https://github.com/TheAlgorithms/C
49 lines
923 B
C
49 lines
923 B
C
// Recursion problem
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// Given the denominations of currencies available in a system, find the number
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// of ways an ATM machine can generate notes for an entered amount N.
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#include <stdio.h>
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#include <stdlib.h>
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int ways(int n, int *a, int k)
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{
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if (n < 0 || k < 0)
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return 0;
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if (n == 0)
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return 1;
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if (k == 0)
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return 0;
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return ways(n, a, k - 1) + ways(n - a[k - 1], a, k);
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}
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int main()
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{
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int m;
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int t;
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int n;
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printf("Number of coins? ");
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scanf("%d", &m);
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int *coin = (int *)malloc(m * sizeof(int)), i;
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for (i = 0; i < m; i++)
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{
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printf("coin? ");
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scanf("%d", &coin[i]);
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}
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printf("---- your requests --- \n");
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while (1)
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{
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printf("amount? exit(0) ");
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scanf("%d", &n);
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if (!n)
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{
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break;
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}
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printf("%d\n", ways(n, coin, m));
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}
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free(coin);
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return 0;
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}
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