46 lines
781 B
C
46 lines
781 B
C
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#define SWAP(a,b) temp=(a);(a)=(b);(b)=temp;
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float select(unsigned long k, unsigned long n, float arr[])
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{
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unsigned long i,ir,j,l,mid;
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float a,temp;
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l=1;
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ir=n;
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for (;;) {
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if (ir <= l+1) {
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if (ir == l+1 && arr[ir] < arr[l]) {
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SWAP(arr[l],arr[ir])
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}
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return arr[k];
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} else {
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mid=(l+ir) >> 1;
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SWAP(arr[mid],arr[l+1])
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if (arr[l] > arr[ir]) {
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SWAP(arr[l],arr[ir])
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}
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if (arr[l+1] > arr[ir]) {
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SWAP(arr[l+1],arr[ir])
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}
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if (arr[l] > arr[l+1]) {
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SWAP(arr[l],arr[l+1])
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}
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i=l+1;
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j=ir;
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a=arr[l+1];
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for (;;) {
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do i++; while (arr[i] < a);
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do j--; while (arr[j] > a);
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if (j < i) break;
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SWAP(arr[i],arr[j])
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}
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arr[l+1]=arr[j];
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arr[j]=a;
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if (j >= k) ir=j-1;
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if (j <= k) l=i;
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}
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}
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}
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#undef SWAP
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